Home | News | Road Tests Lexus IS 250C arrives Next Car is about to road test the new Lexus IS 250C. Stay tuned for our report. Home > News > Lexus 4th September, 2009 Lexus has launched the all-new IS 250C, the first body variation of the marque's most successful sedan - the IS 250. IS 250C features a three-piece metal folding roof that transforms the vehicle from a coupe to convertible in just 20 seconds. Dynamically, the Lexus IS 250C has been designed to combine the driving performance traits of a sedan, with the open air enjoyment of a convertible. The IS convertible is powered by Lexus' proven 2.5-litre quad-cam V6 engine, developing 153 kW of power and driving the rear wheels via a six-speed sequential transmission. The new IS 250C also maintains the IS sedan's highly efficient aerodynamics, achieving an overall coefficient of drag of just 0.29 - a figure some sedans cannot achieve. Lexus Australia chief executive, John Roca, said that the launch of the Lexus IS 250C marks a significant milestone for the luxury marque. "The launch of the IS convertible marks the first body derivative of the IS Line for Lexus in Australia." "IS 250C has been re-engineered to ensure that it is one of the most enjoyable, yet durable, convertibles on the market." "IS 250C is truly a convertible for Australian conditions, tested and proved in the harsh Australian outback." "IS 250C has been designed to offer occupants a comfortable and enjoyable ride no matter what the road or climate." "IS 250C combines the best traits of a sedan and a convertible, delivering a vehicle that is just as enjoyable to drive as it is to look at." "With IS 250C, we continue to forge ahead with growing our product offerings locally, while growing our brand's reach and appeal," said Mr Roca. A word (or two) from the Chief Engineer "Our theme in developing new IS Convertible was 'the open'. It exemplifies the open feeling of the car, the open roads it would travel on and the open space its passengers would experience. Convertibles are difficult to engineer, especially ones with three-part hard-top roofs. IS 250C's roof was designed and engineered in-house. We had three major goals at the start of vehicle development. Firstly, we wanted to produce a quality roof that would compliment the overall exterior - because this is the first convertible IS. Secondly, we wanted to maintain the vehicle's driving performance and rigidity, whether the roof was up or down - here we used IS 250 sedan as a benchmark. The third goal was to ensure a great experience for the IS Convertible's driver and passenger. While IS Convertible is our first genuine four-seat convertible, it is not our first for the marque. With the Lexus SC we have experience and success in engineering a folding hard-top roof. So to begin, we created an electric mechanism to power the roof rather than a more traditional hydraulic system. We found the electric system provided a quieter, smoother, more precise and elegant movement. We also worked hard to eliminate leaks and minimise noises, while optimising the roof's open and closing speeds - with some of this testing conducted in Australia. Furthermore, we wanted to ensure the vehicle's performance was not compromised, top up or down, and that IS 250C performed as closely as possible to the IS sedan. We are confident that with IS 250C we have developed a vehicle that combines the best traits of a sedan and a convertible, it is a welcome addition to the IS Line and the high standards set IS 250 and IS F." Lexus IS 250C proved in the harsh Australian sun The Lexus IS 250C has undergone an intensive development testing programme that took in some of the harshest conditions - including the Australian outback. In early 2008, Australian engineering staff tested IS 250C for dust intrusion, air-conditioning, roof and driving performance in the Northern Territory. Roads between Alice Springs and Darwin were used to test overall durability of the vehicle, with emphasis on dust sealing and roof integrity. Limits of climate control performance were tested by engineers in the heat and humidity of Darwin. Climate control testing involved a process called heat soaking, where a black vehicle was left closed and unprotected in the broad daylight, allowing internal temperatures to reach in excess of 100 degrees. After four hours in the sun the vehicles were then started and climate control units were evaluated for performance and cooling times. Engineers also carried out real world testing on aerodynamic performance to ensure that - with roof up or down - the Lexus IS 250C occupants were not buffeted by wind. The results of the Australian testing were fed back to Lexus engineers resulting in revisions to climate control systems and dust sealing. Engineers also tested the strength of roof locking mechanisms on corrugated roads. Testing confirmed that scuttle shake, when a closed roof rubs against the windscreen surround, was minimal on even the harshest roads. Lexus Australia, Chief Executive John Roca said that the testing cements Australia's importance for the global marque as one of its testing centres. "Australia has played host to the testing of numerous Lexus models including the first ever Lexus - LS 400 - and the LX 570 luxury SUV," said Mr Roca. "IS 250C is truly a convertible for Australian conditions - it has been designed to offer occupants a comfortable and enjoyable ride no matter what the road or climate." "Australian engineers were extremely impressed with IS 250C's performance, noting that dust sealing and lack of scuttle shake were the best they'd seen in a convertible," said Mr Roca. Lexus IS 250C to attract diverse customers For the first time in Lexus history, the luxury marque will offer a genuine four-seat convertible - the all-new IS 250C. The Lexus IS 250C will attract a new array of customers to the Lexus 'stable'. These customers see owning a convertible as a lifelong goal and an individual pursuit. They are not concerned with the stereotypical values that are associated with convertible drivers. These customers are more likely to not have children. They will be either young professionals, or empty nesters who wish to purchase their long-term "goal" vehicle. They may not have previously considered a Lexus, they are not necessarily drawn to any one badge and are not concerned about mass trends, but value the personal reward that comes with driving "their" convertible. Therefore, the Lexus IS 250C is likely to attract 'conquest' sales from other luxury convertibles on the market. These consumers are keen to break away from the crowd and be seen as a leader, an individual and someone who chooses a vehicle for personal reasons. Lexus Australia Chief Executive, John Roca said that IS 250C is a further 'halo' vehicle for the IS Line. "Just last year, we had but one model in the IS 250 range and that was a sedan. Today, we have a sedan, a performance sedan in IS F and a convertible." "IS 250 is one of the best-selling luxury sedans in Australia and IS 250C will strengthen the popularity of the model." "Sometimes it's what you take away that moves you forward and that's exactly what this coupe-convertible has done to the IS Line and the Lexus brand. We've taken away the roof, but grown IS' appeal across the luxury market." "The fact that IS 250C offers greater space, unique styling and outstanding performance and value increases the attraction for customers that are looking to stand out from the crowd," said Mr Roca. Lexus IS 250C range offered in three models Lexus IS 250C will be available in three model grades - Prestige, Sports and Sports Luxury. All models will feature Lexus' proven 153 kW, 2.5 litre, V6 petrol engine, matched with a six-speed sequential transmission driving the rear wheels. All models receive six airbags, reversing camera with guide assist and Lexus' unique VDIM stability control system. VDIM integrates simultaneous command of every appropriate system (VSC, EBD, TRC), providing independent wheel control to help keep the vehicle on the desired trajectory. VDIM begins control functions in stages, before the vehicle's performance limit is reached. Sports and Sports Luxury models gain Lexus' radar Active Cruise Control (ACC) and the Lexus Pre-Collision System (PCS). Radar-controlled PCS optimises pre-collision seatbelt and emergency braking efficiency. If the system senses that an impact is unavoidable, it prepares the car's pre-collision seatbelt and Brake Assist (BA) systems. PCS features a millimetre-wavelength radar sensor to detect obstacles in front of the car and a dedicated computer that monitors vehicle speed, steering angle and yaw rate. From the exterior, vehicles will feature halogen headlamps, LED tail lamps, fog lights, rain-sensing windscreen and puddle lamps. Sports Luxury gains High Intensity Discharge headlamps with AFS. Prestige models will feature 10-spoke, 17-inch alloy wheels with Bridgestone 225/45 R17 tyres front and 245/45 R17 tyres rear. Sports and Sports Luxury models feature five-spoke, 18-inch shadow chrome alloy wheels with Dunlop 225/40 R18 tyres front and 255/40 R18 tyres rear. All models receive Lexus touch screen satellite navigation and an seven-inch multi-information display, heated seats, electro chromatic rear vision mirrors, parking sensors and space saver spare. Interior features in Prestige and Sports models include an eight-speaker Premium Lexus Audio system and silver interior trim. Sports Luxury models receive a 12-speaker Mark Levinson Audio system, electro chromatic side mirrors, Lexus smart entry key card, unique interior trim options, while cooling is added to the seats. Lexus IS Convertible pricing adds heat to convertible market Lexus IS 250C will come to market with three model grades, starting at $79,900* for the Prestige model. The Sports and Sports Luxury models will retail for $84,900* and $99,900* respectively. Lexus Australia Chief Executive John Roca said that IS 250C is a welcome addition to the Lexus range. "The luxury convertible market is highly competitive and IS 250C brings a new look and approach to the segment, one that we believe will resonate with consumers." "In this market segment, price is less imperative - IS 250C will be purchased for emotional and personal reasons." "Lexus however, also adds an element of rationality to that decision - offering a vehicle that is unmatched for its quality, reliability and specification." "Since eligibility, Lexus has continually topped customer satisfaction and vehicle quality studies." "Lexus desire to develop the world's best vehicles is in our corporate DNA - it's our own pursuit." "In the luxury market though quality, the latest technology and specification is expected and something that isn't optional - with Lexus, customers get it all standard." "Unlike our rivals, we've long believed that customers need simplicity in their ownership and purchase experience." "Lexus achieves this by offering vehicles that are highly specified as standard, which in turn further benefits the customer as we have the ability to offer sharp pricing due to the reduced complexity of our model line-up." "Customers, after all, are the key here and IS 250C will bring new customers to the brand, but it's the long term experience that ensures they stay with us." "Our pricing is not apologetic - it's realistic, in our relatively short history we constantly make the competition stand up and take notice and the end result is consumers benefit," said Mr Roca. NOTE* Manufacturer's list prices are provided for comparison purposes only. They do not include dealer delivery or statutory charges. Lexus IS 250C gets foundations right Lexus has redesigned IS 250 body structure and chassis to support the conversion to an open-top vehicle. New Lexus IS Convertible has optimised dynamic performance, ride comfort, crash worthiness and durability, coupled with low interior noise levels. Lexus used its extensive Computer-Aided Engineering (CAE) capability to re-evaluate the body from scratch for optimum positioning of various braces. The dynamic characteristics of the prototype body design were confirmed in an exhaustive road-test programme. The new body has larger-section rocker panels and strengthening measures around the cabin perimeter. Three grades of high-tensile-strength sheet steel have been used to optimise rigidity of the body shell, while meeting strict weight targets. The three grades of high-tensile steel used in the body are 60 kg, 100 kg and 150 kg. The highest grade steel - hot-pressed 150 kg grade - is used to reinforce the centre section of the A-pillar. Unique to Lexus IS 250C is the use of high-tensile steel in the upper and lower sections of the A-pillar, the side collision cross member, four lateral floor reinforcements (under the front seats) and the rear section of the main chassis members. The under-floor has been extensively braced front and rear to enhance body rigidity and provide a stable platform for IS 250C's purpose-developed suspension calibration. Torsional rigidity features include a tubular cross-brace behind the dashboard, bulkheads in the rocker panels immediately under the A-pillars, an additional rear floor cross member adjacent to the rear axle and a large gusset on the rear quarter section of cabin perimeter. Collision strength measures include larger-section rocker panels, a floor cross member that joins to the B-pillars and significant reinforcing of the A-pillars. Lexus IS 250C's body has new rocker panels that are 29 mm wider and 61 mm higher in section than the sedan rocker panels, and pressed from thicker section sheet. The new rocker design increases torsional and flexing rigidity. The rockers were designed with minimal recessed areas to maximise rigidity. The additional rear floor cross member is designed to optimise rigidity. It is a large-profile cross member with a linear shape that joins the rear members where they "kick" over the rear axle, for clearance. In addition, IS 250C has outer and inner reinforcements around the cabin belt line to increase strength, rigidity and passive safety. There was a need to balance body rigidity and collision strength. Seven Under-floor Braces: The Lexus IS 250C employs seven under-floor bracing elements. A front V-brace made from oval-section tube connects the front suspension member to the rocker panels to enhance torsional and flexural rigidity of the whole body. Front torque box braces have been positioned between the front side member and the forward end of the rocker panel. These braces enhance joint rigidity near the torque box and reduce vibration near the front footwell to increase ride comfort. Lexus IS 250C has five interlinked sets of braces at the rear. It has a large under-floor trapezoid brace, integrated with the tunnel brace. The tunnel brace is larger than the US sedan tunnel brace and alleviates the need for a pipe brace in front of the fuel tank. The new trapezoid brace integrates with the front under-floor brace with the tunnel brace and connects it with the rear end of the under-floor reinforcement. The combination of these braces suppresses shear deformation of the floor at the rear end of the tunnel to improve ride comfort and handling stability. Lexus IS 250C has an inner rear rocker brace (also known as a rear torque box brace), to connect the reinforcement under the front floor in a slanted position from the inner rocker reinforcement. It enhances body joint rigidity in the rear of the vehicle for increased ride comfort. Under the fuel tank, IS 250C has a large "M" shaped brace that connects to the trapezoid brace. The design is slanted compared with the longitudinal brace under the IS sedan fuel tank. It is designed to increase body torsional and flexural rigidly, working in conjunction with the trapezoid brace to further boost ride comfort and handling stability. There is also a V-shaped rear brace connecting the rear inner rocker and rear floor cross-member via a mounting bracket on the rocker panel to optimise torsional rigidity for the rear body. It is designed to enhance the adhesion point rigidity of the rear suspension member. A solid flat bar is used for the rear V-brace to enhance strength while still allowing access to components under the floor. In addition, the Lexus IS 250C has a rear suspension-member brace that connects the fixed part (rear side) of the rear suspension member laterally to the V-brace. It enhances the effectiveness of the V-brace and hence the increases the adhesion joint rigidity of the rear suspension member - to increase ride comfort and handling stability. Lexus IS 250C features 2.5 litre V6 engine The new IS 250C has Lexus' proven 2.5-litre Quad Cam multi-valve direct-injection dual VVT-i V6 engine. The all-alloy Lexus 4GR-FSE D-4 (direct-injection, four-stroke, petrol) engine delivers 153 kW of power at 6,400 rpm and 252 Nm of torque at 4,800 rpm. The V-configuration engine contributes to the IS design goal of concentrating mass within the wheelbase. The direct-injection petrol V6 combines impressive performance and fuel efficiency. It has official combined ADR81/02 fuel economy of 9.3 litres per 100 km* and CO2 emissions of 219 g/km. The 2.5-litre V6 engine is matched to a six-speed electronically controlled automatic transmission with shift paddles on the steering wheel. NOTE * Fuel consumption will vary depending on driving conditions/style, vehicle conditions and options/accessories. Source of fuel consumption data: ADR81/02 combined cycle. Lexus IS 250C six-speed sequential transmission Lexus IS 250C has a six-speed multi-mode intelligent automatic transmission with a sequential shift, using either an S-mode gate shift lever or paddles on the steering wheel. The steering wheel has the up-shift metallic paddle on the right and the down-shift paddle on the left, in the traditional manner. A gear position indicator has been included in IS 250C's multi-information display. IS 250C's combination of dual VVT-i Quad Cam V6 engine, electronic throttle and six-speed automatic transmission is designed to optimise driveability, acceleration feel, shift quality and fuel economy. The close-ratio Lexus A960E ECT (Electronically Controlled Transmission) uses triple planetary gears and has ratios of: first, 3.538; second, 2.060; third, 1.404; fourth, 1.000; fifth, 0.713; sixth, 0.582 and reverse, 3.168. It is matched to a 3.909:1 final drive ratio. Lexus last year upgraded IS 250's automatic transmission with a manual override of the paddle shifts in D mode, while down-shift times were reduced from 1.4 seconds to eight tenths of a second for improved drivability. The latest iteration of the A960E transmission has an impressive list of features when operating under the D mode, including Lexus-first temporary sequential mode, which allows the driver to specify a fixed range of ratios to be used and paddle-shift gears within that range. The dashboard shift-range shows the gear in use or D when this function is used. The transmission will revert to automatic operation if the vehicle is stopped, the accelerator is depressed for more than a certain period of time, or the driver holds the up-shift paddle for more than one second. Lexus engineers used triple planetary gears in the A906E transmission for package efficiency, while refined electronics and state-of-the-art hydraulic technology ensure Lexus' trademark smooth shifting. Special attention was paid to the selection of friction materials and automatic transmission fluid to help ensure smooth torque converter lock-up. The multi-mode transmission can be driven as an automatic, or used to shift gears manually, using the S-Mode position on the shift gate or the shift paddles. The transmission's electronic control unit momentarily retards the ignition during manual down changes to ensure smooth shifting. The gear position indicator in the combination meter automatically switches to the S position when the manual mode is selected to display the relevant gear. Road condition support control and intelligent transmission software gives the Lexus IS 250C automatic smooth shifting performance in automatic mode - particularly, on winding or hilly roads. The Lexus artificial intelligence (AI Shift) transmission algorithm is designed to manage the shift regime according to road conditions and driver behaviour. It uses data on accelerator pedal angle and rate of change, throttle angle and engine speed. The Lexus AI Shift can adjust the shift pattern to suit different drivers and provide engine braking for hill descents. The system works in conjunction with IS 250C's intelligent electronic throttle. The salient characteristics of the AI Shift system are as follows: • has advanced hydraulic control and electronic control transmission (ECT) technology to provide smooth shifting; • manages the timing of torque reduction and speed control, through the manipulation of the clutch brake system, according to data on the operation of the accelerator pedal and throttle angle; • has a "no up-shift" mode to hold the transmission in gear, rather than down-shifting briefly for improved driveability on hill ascents; • has a "down-shift and hold" mode to provide improved driveability on hill descents. IS 250C brakes Lexus IS Convertible's brake system includes a full suite of Lexus' electronic chassis dynamics technology. All IS 250C models have Vehicle Dynamics Integrated Management (VDIM), Traction Control (TRC) and Hill-start Assist Control (HAC). Lexus IS 250C has 296 mm x 28 mm ventilated disc front brakes with two-piston aluminium callipers and high-friction brake pads. The rear brakes feature 310 mm x 18 mm ventilated discs and are larger than those found on IS sedan. IS 250C has four-channel, four-sensor ABS with Electronic Brakeforce Distribution (EBD) and Lexus Brake Assist (BA). Lexus IS 250C suspension smoothes the way IS 250C has redesigned rear suspension towers with increased rigidity, including the addition of a suspension tower ring. The towers have been lowered compared with the sedan, to provide luggage room space for the folding roof. Lexus IS 250C's suspension chassis package includes electric power-assisted steering, as well as Vehicle Swerve Control (VSC), Traction Control (TRC) and Hill-start Assist Control (HAC). The new calibration for IS 250C's double-wishbone front suspension includes four key changes from the sedan calibration: purposed-designed bushings for the upper wishbone bush and lower number one bush, revised spring rates, revised damper curves and a revised stabiliser bar shape. The new calibration for IS 250C's rear suspension includes purpose-designed bushings for every bush in the multi-link suspension layout. The rigidity of the suspension member mount has been optimised by using high damping material. In addition, the convertible's rear suspension has revised spring and damper rates. Substantial front and rear cross-members support the suspension hardware, increasing suspension rigidity and driving stability. The front cross-member is made of aluminium, with large, liquid-filled bushings at the rear mount of the lower arms to reduce noise, vibration and harshness (NVH). The ball-joint-mounted stabiliser bars are fitted front and rear to minimise uncontrolled body roll. Lexus IS Convertible has high-performance monotube dampers for increased performance and fine tuning at low damper velocities. This optimises body control, road tracking capability and ride comfort. Lexus IS 250C also features a front/rear tyre size differential, with 225/45 R17 front tyres and 245/45 R17 rears on the Prestige model, and 225/40 R18 front tyres and 255/40 R18 rears on the Sports model and the Sports Luxury model. IS 250C's underbody aerodynamics package was redesigned to reduce noise and ensure the car's handling characteristic remains constant as speed varies by minimising fore and aft movement of the car's aerodynamic centre of pressure. The engine undercover is stepped to provide a series of venturis - low-pressure areas are located under the front of the car - thereby increasing downforce. The rear floor diffuser has two vertical fins and an airfoil to optimise stability. There are aerodynamic spats in front of the wheels. IS 250C has a large footprint on road for its overall dimensions. It has a wheelbase of 2,730 mm, and front and rear track of 1,535 mm. Sports and Sports Luxury models have a rear track of 1,525 mm. Optimised Geometry: IS 250's suspension geometry was designed to provide anti-dive, anti-lift and anti-squat characteristics. The front suspension geometry has been designed to enhance initial camber and caster change rate during suspension travel, and maximise driving stability. The geometry also improves stability under brakes. Front and rear roll centre heights have been optimised to minimise postural change during cornering. Cast-aluminium suspension uprights and aluminium brake callipers are used front and rear to minimise unsprung weight. The front suspension arms are fabricated from high-strength steel sheet to increase rigidity and durability and reduce weight. IS 250C's front and rear suspension includes urethane bound-stoppers and upper and lower isolators to increase rigidity and reduce NVH. The suspension upper supports have a load input dispersion construction to provide support while dispersing the input loads from the damper, coil spring and bound-stopper. This also improves ride comfort and reduces NVH. Front Suspension and Steering: Lexus designed IS 250C's front double-wishbone suspension and steering to optimise grip, linear yaw response, steering precision, straight-line stability and turning radius. The suspension design has high-mount upper arms, for maximum suspension travel and reduced toe change during suspension stroke, which maximises tread width on the road. The high-mount upper arms reduce the offset between the tyre centre and the kingpin axis at axle centre height. This reduces the movement around the kingpin and the chance of steering flutter. The suspension components have been designed to maximise front wheel turning angle and achieve a turning circle of 10.2 metres. The steering rack has been positioned ahead of the axle line to provide smooth cornering response during highway driving. Monotube Dampers: IS 250C's high-pressure, gas-filled monotube dampers provide linear handling response to steering inputs, and a flat-riding characteristic. The dampers have multi-leaf-type linear control valves to provide progressive damping and start the damping force at extremely low piston velocities. Increased damping force at ultra-low piston velocities reduces unsprung wheel stroke, thereby improving road tracking and ride comfort. The monotube dampers also provide greater control of ultra-low-speed damping force for improved body roll control and initial damping characteristic. In addition, the multi-leaf-type linear control valves provide smooth, more progressive damping in the transition between bound and rebound. Monotube dampers have a range of benefits over conventional twin-tube dampers, including a significantly larger piston diameter, significantly increased range of damper tuning, increased durability and greater resistance to damper fluid cavitation. The monotube damper design also provides for increased oil volume and means the "working" oil is adjacent to the damper body, thereby increasing heat dissipation. The large diameter increases damper rigidity and gives the suspension engineers greater scope with valves and orifices to control to damper force at different damper velocities. In addition, IS 250C's monotube dampers have internal rebound springs. Lexus has developed new-generation damper oil seals during the Lexus IS 250 development programme, to better tune damper gas pressure rates and friction rates, and improve body control. Lexus IS 250C wheels and tyres New Lexus IS 250C has unique high-gloss coated alloy wheels and a front/rear tyre size differential. Lexus IS 250C Prestige model has 17-inch silver metallic coated wheels with two sets of five spokes to provide a multi-layered ten-spoke configuration. It has 225/45 R17 front tyres and 245/45 R17 rears. The Sports and Sports Luxury models have 18-inch shadow chrome metallic coated five-spoke wheels, with 225/40 R18 front tyres and 255/40 R18 rears. Lexus IS 250C is quiet - roof up or down New IS Convertible was designed for low interior noise levels with the hard top up or down. Lexus IS 250C's highly rigid body design and its all-alloy V6 engine form the basis of the vehicle's NVH credentials. Special attention was paid to over and under-body aerodynamics to minimise wind noise. In addition, Lexus has adopted a range of NVH counter measures throughout the vehicle. For example, IS 250C has exclusive rear suspension member mounting bushings, to support the changed body characteristics of the open-body design. Damping characteristics that impact in the 15-20 Hertz range ('throbbing vibration' sensation) have been reduced. High-rigidity application type damping materials, asphalt sheets and resin retainer have been strategically placed on the cabin floor to reduce NVH, while maintaining strict weight targets. The luggage panel has a dynamic damper to cancel vibration generated by the suspension. Polypropylene sheet foam material has been placed in the roof header to prevent sound generation and resonance. Foam material has been placed in the corner of the A-pillars and GFF material at the base of the A-pillars to act as air flow cut-off structures. Plated sound absorbing material has been added to the inner rear quarter panels and quarter liner to provide sound insulation. Sound-absorbing sponge has been added under the base of the roof links and in the bent duct. GFF material has been positioned in the roof sides and sponge material on the roof inner side to act as sound insulators and/or absorbers. Lexus trademark Thinsulate material has been added to the inside liners of the front wheelhouse. Super Olefin Polymer with ten per cent rubber (EPR) content has been adopted for the floor cover material to provide flexibility without sacrificing rigidity. Sound absorbing materials, including urethane, carpet, glass fibre and felt have been strategically positioned throughout the interior and the boot to provide efficient noise reduction measures. Lexus IS 250C has responsive steering Lexus IS Convertible has electric power-assisted rack and pinion steering for optimum steering feel and reduced fuel consumption compared with hydraulic power-assisted steering. The highly responsive steering system provides a road speed-sensitive power-assist curve. All IS 250C models have power tilt and telescopic steering column adjustment with memory, and 3.16 turns lock to lock. Electric Power Steering (EPS) saves energy in high-speed and straight-line driving, as virtually no electric current is required. The energy requirement increases with wheel turning angle, particularly at low road speeds. However, hydraulic power steering requires continuous operation of the hydraulic pump. EPS has the additional environmental benefit of eliminating the need for hydraulic oil (and a hydraulic oil reservoir) in the steering system. It also reduces noise. The key components in Lexus EPS are a torque sensor in the steering box to detect steering effort, and a controller to calculate torque assistance according to that effort. The controller then drives the brushless direct-current motor based on the output value from the torque sensor and the motor rotation angle sensor. The motor, ball-screw reduction gear and rotation sensor are integrated into the steering gear housing. A lightweight steering controller contributes to package efficiency and overall weight saving. Lexus IS 250C features sophisticated roof Lexus IS Coupe-Convertible's sophisticated electrically powered metal hard top can open or close in 20 seconds, using an array of 13 motors and 33 sensors to give smooth and silent operation. The roof control software includes a speed brake control function, so the roof descends slowly and smoothly when closing. The roof can only be operated when the vehicle is stationary. The electronic roof control unit interacts with the power window controls to lower all power windows while the roof is opening and closing. Holding down the roof function button once the roof has completed its operation will close all windows again - provided the vehicle is still stationary. The IS 250C roof has three sections, including two aluminium roof section and 3.1mm thick reinforced glass rear window. It folds into the boot for open-top motoring. Roof system at a glance New Lexus IS Coupe Convertible has a three-part roof structure and four-link electrically powered roof operating mechanism. The roof has two locks, a front lock assembly where the roof meets the roof header (above the windscreen) and a rear roof lock that secures the join between the number two roof panel and the rear window panel. The four links are a link base, control link, bracket link and rail link. The link base is aluminium to minimise weight. The side and main parcel trays have special mechanisms to ensure they move clear of the roof when it is opening and closing. The roof link motor has a built-in Hall IC that outputs a pulse signal to the hard-top ECU in accordance with the motor speed - to achieve motor speed control. The motor-speed control ensures smooth closing of the roof against the windscreen surround when closing the roof. A separate motor controls the boot lid operation. It has a Hall IC to synchronise operation with the roof and the roof-speed control. The boot lid is designed to open forward for hard-top opening and closing and open to the rear for luggage loading. The luggage door rear lock assembly has a link mechanism so it can move up and down in conjunction with the boot lid when the lid opens forward. It is designed to ensure there is no interference between the boot lid and rear bumper during roof opening and closing. Lexus IS 250C blends sedan and convertible Every panel of new Lexus IS 250C - except the bonnet and front quarter panels - has been redesigned to achieve a unique exterior design. IS 250C draws on L-Finesse styling DNA to deliver a design that is instantly recognisable as a member of the Lexus family and IS 250 range, but still posses an identity of its own. IS 250C's development team sought to deliver a design that satisfied "dual mode style" of elegance and sports - with the roof up or down - while still holding true to IS 250 sedan's original design. Additionally, the Lexus design team wanted to develop a vehicle that featured the sweeping lines of a traditional coupe, with the visual appeal of a convertible. The side of IS 250C features a pronounced belt-line that runs continuously from the front guards through to the rear lights and blends into the ducktail boot lid. The side window glass area forms an arrowhead shape - a signature of Lexus' L-Finesse design philosophy. The front is identifiably IS with a sharp crease line that flows down from the bonnet to the edges of chrome grille, then continues down toward the lower bumper radiator intake, which is bound by newly designed elliptical fog light and air intake surrounds. The rear view features a clean, continuous design, with flowing bumper corners and a strong bumper shape, which flows inward towards the exhaust. The rear has also been designed to minimise the "bulk" area that is prevalent in convertible designs by employing a unique sculpted ducktail boot lid and rear quarter panels. An integrated taillight in the rear spoiler adds to the visual appeal while aiding the convertible's overall aerodynamics. Rounding out the rear of the Lexus IS 250C is an all-new combination tail-lamp cluster featuring LEDs and two distinct horizontal lines that emphasise width. Lexus IS 250C has aerodynamic body Lexus IS 250C has been designed to maintain the efficient aerodynamic design of its sedan sibling. Lexus engineers achieved a final co-efficient of drag of just 0.29, just 0.02 points higher that the IS sedan. With the roof down, turbulence in the passenger compartment is kept at a minimum, even without the fitment of a r ear wind deflector, due to the IS 250C's efficient design. The aerodynamic body aides not just fuel consumption, but wind noise - a critical element in convertibles. The aero-efficient design has been achieved through the adoption of uniquely designed boot, windscreen header, tail lamps, door sills and front bumper bar. Lexus engineers took into account the length of the cabin area and height of rear headrests to ensure that flow over the vehicle was as smooth as possible. IS 250C also adopts specifically designed underbody diffusers that ensure airflow under the vehicle was just as efficient as the airflow above. The underbody of IS 250C contributes to an overall negative pressure area under the vehicle, essentially sucking it to the road. The underbody aerodynamic package makes for a venturi effect at the front to smooth airflow, a flat bottom effect in the middle and a diffuser at the rear to disperse and smooth exiting airflow. Lexus IS 250C has boot loads of space Lexus IS 250C is the only vehicle in its class to accommodate a full-size (nine-inch) golf bag with the hard top stowed and the luggage cover in place. With the roof down, IS 250C offers 205 litres of storage space, while with the roof up, boot volume is to 553 litres. With the roof up, IS 250C's boot is able to swallow two full-size (nine-inch) golf bags along with two 77 litre suit cases. A 50 mm increase in rear overhang and a cleverly designed hinge system - which does not encroach into the storage space - combine to improve overall boot space. The luggage cover features four sensors to warn operators that objects are in the boot to ensure that the roof cannot be operated while the boot is full. The boot also neatly houses a first aid kit, tool bag, valet kit (for tyre changing) and a space saver spare wheel. Lexus IS 250C seats maximise comfort Lexus IS 250C 2+2 seating layout features seats designed to maximise comfort and space for front and rear occupants. IS 250C features a unique arched seat design that provides an additional 20 mm of leg and knee room for rear seat passengers without sacrificing front passenger posture and comfort. IS 250C's 542 mm of leg room from hip point to seat back ensuring passengers have ample room in the rear. For roof down motoring, Lexus engineers increased the heated areas of the shoulder, seat back and base regions of IS 250C's front seats by 20 per cent. Cool airflow to the seats has also been increased to aid with warm weather motoring on Sports Luxury models. Front seats have been designed to offer a maximum forward movement of 240 mm and an eight degree forward stow, to assist with rear passenger entry. IS 250C's front seats feature a unique combination handle, belt guide and seat control mounted in the 'shoulder' of the seat. The belt guide allows front passengers to stow the seatbelt in an easy to reach manner when belts are unbuckled while assisting with belt movement in crash situations. Rear seats feature a unique magnetic clasp to hold the centre mounted rear belts in place when not in use. Rear seat passengers benefit from sculpted bucket seats with a centre console. The centre console and body side mouldings are bound by leather accented wrapped pads to ensure maximum comfort, while the centre console houses a twin cup holder. Head room is a breeze in Lexus IS 250C Lexus IS 250C has been designed to ensure that front and rear passenger head room and comfort was not compromised by the convertible's all-new three-piece folding roof. To achieve this, Lexus engineers adopted a unique roof lining. The scalloped, full-fabric, roof lining ensures that headroom in the IS convertible is comparable to that of the IS 250 sedan. Furthermore, rear seats have been mounted 30 mm further inboard than the sedan to allow a lower seating position and less intrusion from roof pillars. The overall result is effective headroom of 918 mm in the rear. Front occupants also receive a generous 974 mm of effective headroom with the roof in place. Engineers also ensured that roof down, front and rear passengers were not buffeted by wind flowing over IS 250C. Windscreen angle, header shape, cabin length and height of the boot, were all taken into consideration to ensure that occupants received gentle airflow through the cabin, even at speeds in excess of 100 km/h. Engineers undertook real world testing in a number of countries, including Australia, to confirm that cabin comfort was as expected from computational and wind tunnel evaluations. Climate control ensures passengers keep their cool Lexus IS 250C features a custom-designed climate control air conditioning system, tailored to maintain temperature level regardless of whether the convertible's roof is open or closed. IS 250C's climate control system features an Open mode speed-sensitive control that monitors and alters climate control performance when the roof is open. The Open mode speed control can alter temperature, adjust outlets and double airflow output based on ambient temperatures, vehicle speed and sunlight to maintain interior temperature - be it heating or cooling. IS 250C employs independent controls for both the left and right-hand sides of the cabin. The system includes the hallmark Lexus cabin comfort technologies of a smog ventilation sensor and an easy-to-change pollen filter in the air conditioning system. The smog sensor is adjustable for sensitivity, using the controls on the climate control panel. It automatically changes the air intake from 'fresh' to 'recirculate' if a sensor located behind the radiator grille detects uncomfortable levels of carbon monoxide, hydrocarbons or oxides of nitrogen. Mark Levinson audio raises the roof on the Lexus IS 250C IS 250C offers occupants two options when it comes to on-board entertainment - open air theatre and cinema. IS 250C Prestige and Sports models will offer an eight-speaker Lexus Premium Audio system and a 12-speaker Mark Levinson audio package developed specifically for the convertible, and will feature solely on the Sports Luxury model. Both systems feature an equaliser system that alters audio settings to maintain the same acoustic field in the cabin regardless of roof position, and places particular emphasis on stopping bass losses. Both systems also feature AUX inputs for portable music devices. The Sports Luxury's Mark Levinson Audio offers a complete 5.1 channel surround sound home theatre experience. Over the Prestige and Sports models system, the Mark Levinson system features a centrally-mounted speaker in the dashboard, tweeters either sides of the rear seat and a sub-woofer in the rear. New interior sets Lexus IS 250C apart IS 250C's interior continues the wraparound cockpit theme debuted on IS 250 sedan, with re-engineering to suit roof-down motoring. A new door design has been sculpted around IS convertible's unique frame, with door and side trim designed to provide continuity and continuous flow from front to back. With the doors closed, a large sweeping line flows from the base of the door through to the upper portion of the rear passenger compartment. Interior gauges and display screens have also been redesigned to ensure ease of use and clear viewing in high ambient light when the roof is down. This has been achieved through the adoption of a higher-contrast multi-information LCD screen, changes in dial colours for greater contrast and the adoption of interior screens that decrease surface reflection. The instrument cluster also features a multi-information display which includes a visual display as to the status of roof operation. It also displays a warning to inform the driver if the roof is not completely open or closed, or an object is too close to perform open and close operation. The interior design is complimented by three unique interior trim colours matched to nine exterior colours for the IS convertible. Mellow White and Black seat will be offered across Prestige, Sports and Sports Luxury, with a unique Silver Pearl interior trim available on Sports Luxury models. The leather trims will be matched to a silver-accented interior trim on Prestige and Sports models, while Sports Luxury models can be specified with Dark Brown and Grey Wood interior trims. Trim accents will feature across the centre console and door arm rests. Lexus IS 250C occupant entry and exit All-new IS 250C presented Lexus engineers with a unique challenge - how to maintain easy entry and exit in a four seat vehicle with only two doors. Doors are now 300 mm longer than that of the IS 250 sedan, and an all-new one-touch walk-in button allows for speedy stowage of the front seats. The one-touch walk-in feature is activated by pressing a button in the front seatbelt locator mounted on the 'shoulder' of each front seat, which moves the front seats forward in one motion. Seat movement times have also been halved over that of the sedan to ensure entry and exit is as fast as practical. Door surrounds have been designed to minimise the risk of tripping or catching clothing on entry and exit. Once rear passengers are seated, the walk-in button can be pressed to return the front seats to the nominal driving position. Rear seat passengers can push the walk-in button or fold the seats via a release handle mounted on the central side of the front seat bolsters. Both Sports and Sports Luxury models also featured Lexus' unique Smart Entry and Smart start systems allowing keyless entry at the touch of a door handle. The proximity key entry system for Sports Luxury further features a slim line key card which is just 3.35 mm thick. Smart Card has an area of 83 mm x 53 mm, making it four per cent smaller than a standard credit card. Smart Card also includes a conveniently concealed conventional metal key, which provides access to the car in the rare event of a system failure. When the Smart Card is between 0.7 and 1.0 metres from the locked door, the key communicates with a transmitter built into the door handle and matches ID codes. IS 250C ensures all is at hand Lexus IS 250C ensures ready access to any feature or function from the moment drivers' approach the vehicle. IS 250C's puddle and interior lights illuminate to welcome occupants through the use of Lexus' Smart Entry system and proximity key. The convertible's roof is controlled by a switch located just to the right of the steering column. IS 250C's front seats feature a unique seatbelt locator, which does away with having to reach rearward to grab seat belts. Foldable rear head restraints - that can be remotely operated via a lever discreetly housed in the rear cabin centre console - aide with exterior vision. Front doors feature a new map pocket design that can store A4-size road maps or documents. IS 250C's windscreen header features full-size sun visors with in-built, illuminated vanity mirrors, while driver's side features a slot for stowing fuel cards or garage swipe cards. An interior light cluster is located in the centre of the windscreen header and features a dome light, two LED map lights and a discreet LED lamp that shines down on the centre console. The centre console houses storage areas for two drinks, a centre bin for compact discs, AUX jack for portable music devices, 12 volt power outlet and seat heating controls. Traction control and transmissions mode buttons are located on the left of the steering column, while the steering wheel features controls for audio, phone, cruise control and for Sports and Sports Luxury models radar distancing controls. All other audio and climate controls are housed in the centre binnacle or enacted via the Lexus multi information touch screen located in the centre of the dashboard. Active safety Lexus IS 250C has high levels of active safety thanks to the inclusion of Active Cruise Control and the Lexus Pre-Collision System (PCS) on the Sports and Sports Luxury grade. IS 250C has a new purpose-design chassis and a new suspension calibration. All model grades have Vehicle Dynamic Integrated Management (VDIM), Traction Control (TRC) and Hill-start Assist Control (HAC). The brake package includes 296 mm x 28 mm ventilated disc front brakes with two-piston aluminium callipers, as well as ABS with Electronic Brakeforce Distribution (EBD) and Lexus Brake Assist (BA) as standard equipment. Front and rear fog lamps as standard equipment. Lexus IS 250C also has an electro-chromic interior mirror, parking sonar and rear guide monitor and heated exterior mirrors. IS 250C Sports Luxury has the additional active safety features of rain-sensing windscreen wipers, auto-levelling HID headlamps and AFS while, Sports and Sports Luxury models receive heated exterior mirrors, Active Cruise Control and Lexus Pre-Collision System. Passive safety Lexus IS 250C meets Euro N-CAP frontal offset, side impact and pole impact requirements, as well as the US N-CAP frontal test and side-impact tests. The coupe convertible's safety equipment includes newly developed head and torso side SRS airbags - purpose designed to reduce the chance of head injury in accident when the hard top is down. The new side airbags have a larger impact alleviation area than a conventional side airbag, to include head protection. IS 250C has dual frontal SRS airbags, and driver and front passenger knee airbags and IS 250C Sports and Sports Luxury has the Lexus Pre-Crash Safety system (PCS). Lexus PCS tensions the seatbelts under any of three scenarios: the inter-distance ECU determines a collision is unavoidable; the Vehicle Dynamic Integrated Management (VDIM) and electronic braking ECU determine that emergency braking has been applied; or the vehicle is in an understeer or spin situation. IS 250C's new passive safety features include a seatbelt guide on the "shoulder"' of the front seats. The rear-seat seatbelts are three-point ALR/ELR type, with buckles positioned on the outside of the seats closest to the sides of the vehicle. The sash section of the belt has a re-router system to provide easier buckling of the belt when a small child is riding in the rear seat. Additional passive safety measures include head impact absorbing structures in the A pillar and roof rails and energy absorbing pads in the door and quarter trim to alleviate hip injury. Lexus IS 250C also has a retractable brake pedal and energy-absorbing steering column. Parking sensors New Lexus IS Convertible has an ultrasonic clearance parking system as standard equipment for added convenience. The front and rear bumper-mounted parking ultrasonic sensors alert the driver through a series of beeps and clearance information on the Navigation display screen when the car is too close to an object. The parking sonars and graphics activate on preset clearance areas around the car. There are two ultrasonic sensors in the front bumper, one in each corner of the rear bumper and two back sensors. VDIM New IS Convertible has Lexus' Vehicle Dynamics Integrated Management (VDIM) system as standard equipment. The system, launched in February 2005 in GS 430, was the world's first vehicle stability control technology with active steering control. It included three world firsts: steering control with braking on surfaces with split friction (split mu), steering control with driving (acceleration) on split mu surfaces and steering control in understeer situations. Lexus' VDIM system is designed to improve active safety, vehicle handling and driving enjoyment by providing a total vehicle dynamic package. It seamlessly integrates the proven Lexus active safety systems - Vehicle Stability Control (VSC), Traction Control (TRC), Brake Assist, ABS with Electronic Brakeforce Distribution (EBD) and Electronic Throttle Control with intelligence (ETC-i). Lexus VDIM is designed to appear transparent to the driver and therefore provide smoother, safer and more enjoyable driving. With conventional brake control technology, if the driver brakes suddenly the brake control system detects a locked wheel or the VSC detects a skid, and these systems then stabilise the vehicle's dynamics. With VDIM, the system anticipates a likely skid and begins vehicle and VSC functions in anticipation. VDIM therefore minimises vehicle instability and assists in providing optimum driving stability - by seamlessly combining the VSC and ABS functions. VDIM uses powerful proprietary software to restore vehicle stability by integrating IS 250C's "run, stop and turn" control technologies. They are: ETC-i, the TRC system to individually control power delivery to the rear wheels, and the EPS and provide steering torque assist (active steering control) if required. Occupant protection Lexus designed new IS Coupe Convertible with a comprehensive side collision impact protection structure. The IS 250C has a purpose-designed body with 183 mm by 145 mm section rocker panels, compared with 122 mm by 116 mm rocker panels on IS 250 sedan. The side impact protection structure includes a side collision cross member pressed from 100 kg class high-tensile steel sheet to link the base of the B-pillars. Self-Catering Holiday Accommodation in Denmark, WA ..... more Lexus IS 250C also has an upper cross member, an additional rear-floor cross member, crash boxes on the B-pillar and a door sub-latch mechanism. The sub-latch mechanism consists of a steel striker on the rear end of the door impact beam that engages with an orifice in the B-pillar when the door is closed, to transmit side impact beam load to the lower part of the B-pillar. In addition, IS 250C has an outer an inner reinforcement at the door belt line, to improve strength, rigidly and safety performance. IS 250C's rocker panels have internal bulkheads under the A and B-pillars, to add strength in the horizontal, vertical and lateral planes. There is a boot-shaped reinforcement under the A-pillar, as well as the vertical and horizontal bulkheads. The rocker section under the B-pillar has been reinforced with horizontal and lateral bulkheads, to suppress the chance of surface buckling caused by the height difference with the rear floor cross member. There are two side bulkheads under both the A and B-pillars. The large profile upper cross member is installed in the upper back area - linked to the B-pillar via a substantial gusset. It is designed to optimise torsional rigidity with the open-design body and resist body deformation in a collision. Lexus designed the new IS Coupe Convertible with a comprehensive side collision impact protection structure. New IS 250C has a purpose-designed body with 183 mm by 145 mm section rocker panels, compared with 122 mm by 116 mm rocker panels on IS 250 sedan. The side impact protection structure includes a side collision cross member pressed from 100 kg class high-tensile steel sheet to link the base of the B-pillars. IS 250C also has an upper cross member, an additional rear-floor cross member, crash boxes on the B-pillar and a door sub-latch mechanism. The sub-latch mechanism consists of a steel striker on the rear end of the door impact beam that engages with an orifice in the B-pillar when the door is closed, to transmit side impact beam load to the lower part of the B-pillar. In addition, IS 250C has an outer an inner reinforcement at the door belt line, to improve strength, rigidly and safety performance. IS 250C's rocker panels have internal bulkheads under the A and B-pillars, to add strength in the horizontal, vertical and lateral planes. There is a boot-shaped reinforcement under the A-pillar, as well as the vertical and horizontal bulkheads. The rocker section under the B-pillar has been reinforced with horizontal and lateral bulkheads, to suppress the chance of surface buckling caused by the height difference with the rear floor cross member. There are two side bulkheads under both the A and B-pillars. The large profile upper cross member is installed in the upper back area - linked to the B-pillar via a substantial gusset. It is designed to optimise torsional rigidity with the open-design body and resist body deformation in a collision. HAC Lexus IS Coupe Convertible has the added safety and convenience of a device to ensure smooth take-off on steep hills. Lexus Hill-start Assist Control (HAC) is an automatic function to prevent the vehicle rolling backwards when starting off, and is available on the automatic transmission models. It is particularly helpful on low-traction off-road surfaces. In addition, HAC protects the automatic transmission's torque converter from excessive strain. The system is part of IS 250C's brake-control technology. If the system detects that the vehicle is rolling backwards during a hill start, it automatically applies hydraulic brake pressure to the four wheels, providing ample time for the driver's foot to move from the brake pedal to the accelerator pedal. Lexus IS 250C major technical specifications ENGINE Engine code 4GR-FSE Displacement (cm 3 ) 2,500 cc Engine type Six cylinders, V-formation, 24-valve, DOHC, four valves per cylinder and alloy cylinder block. Fuel type 95 RON ULP (recommended) Valve mechanism Variable valve timing on intake and exhaust valve. Bore x stroke (mm) 83.0 x 77.0 mm Compression ratio 12.0:1 Max. power 153 kW @ 6,400 rpm Max. torque 252 Nm @ 4,800 rpm trANSMISSION Type Six speed automatic sequential shift, electronically controlled with lock-up torque converter Gear ratios   First 3.538:1 Second 2.060:1 Third 1.404:1 Fourth 1.000:1 Fifth 0.713:1 Sixth 0.582:1 Reverse 3.168:1 Final drive ratio 3.909:1 SUSPENSION Type Front Independent, double wishbone, upper A-arm, lower L-arm, coil springs, gas dampers and ball joint mounted anti-roll bar Rear Independent, multi-link type, with castor locating rod, coil springs, gas dampers and ball joint mounted anti-roll bar BRAKES Front 296 x 28 mm ventilated discs, single piston, sliding calliper Rear 310 x 18 mm ventilated discs, single piston, sliding calliper Additional features ABS Electronic Brake force Distribution Brake Assist Active Traction Control Vehicle Stability Control Electronic Brake Control HAC STEERING Type Electric power-assisted high precision rack and pinion Turns lock-to-lock 3.16 Minimum turning diameter - tyre (m) 10.2 WHEELS AND TYRES Prestige 17 x 8J (F & R) Sports/Sports Luxury 18 x 8J (F) 18 x 8.5J (R) Tyres   Prestige 225/45 R17 90W (F) 245/45 R17 95W (R)   Sports/Sports Luxury 225/40 R18 88Y (F) 255/40 R18 95Y (R) Spare Space saver Prestige T125/70 D17 98M Sports/Sports Luxury T125/70 D17 106M BODY/EXTERIOR DIMENSIONS Overall length (mm) 4,635 Overall width (mm) 1,800 Overall height (mm) 1,415 Wheelbase (mm) 2,730 Track front (mm) 1,535 Track rear (mm) 1,535 (17" wheels) 1,525 (18" wheels) Co-efficient of drag 0.29 WEIGHTS/LOADS Kerb weight (kg) 1,730-1,750 Gross vehicle weight (kg) 2,075 CAPACITIES Fuel tank (L) 65 Seating 4 Boot (Roof up) (L) 553 Boot (Roof down) (L) 205 PERFORMANCE Max. speed (km/h) 210 (electronically limited) 0-100 km/h (sec) 9.0 FUEL CONSUMPTION (L/100 km) Fuel consumption will vary depending on driving conditions/style, vehicle conditions and options/accessories. Source of fuel consumption data: ADR81/02 combined cycle. Combined 9.3 Urban 13.1 Extra Urban 7.1 CO 2 EMISSIONS (g/km) Combined 219 Hear Chris Goodsell Talk Motoring On Radio & Internet ..... more More Lexus News ..... here Top of page About | Car Clubs | Home | News | Road Ramblings | Road Tests | Subscribe | Top Drive ©   2009   All rights reserved.   Next Car Pty. Ltd.