BMW Group and PSA Peugeot Citroën have unveiled the state-of-the-art technologies deployed in their new gasoline engines, the first to be jointly developed and produced by their cooperative venture.

Announced in July 2002, the two Companies’ cooperation in gasoline engines is now setting new standards for performance, driving comfort and reductions in fuel consumption and CO2 emissions.

Beginning in 2006, the engines will equip small and mid-size cars produced by the Peugeot and Citroën marques as well as future models of the Mini. Production is expected to eventually total approximately one million units a year.

At a special technology day at BMW Group’s Research and Development Centre in Munich, executives from both companies presented the technical features of two types of engines:

- A 1.6-litre atmospheric engine with a variable geometry turbocharger and a power output of 85 kW (115 hp).

- A 1.6-litre direct injection, compressed turbo engine with a power output of 105 kW (143 hp).

The new models are the first in a family that will eventually comprise engines delivering a range of power outputs from 55 kW (75 hp) to 125 kW (170 hp).

As a result of both groups’ expertise, these engines offer a large number of new features including:

- Variable valve timing.

- Fully controlled oil pump.

- Single belt drive for all ancillary components.

- Cylinder heads produced by lost foam casting.

In addition, several innovations have been developed, including:

- Direct injection to optimize power.

- Twin-Scroll turbocharger to improve response time and driving comfort.

- Self-disengaging water pump to reduce fuel consumption and emissions.

The co-operation between BMW Group and PSA Peugeot Citroën clearly demonstrates that gasoline engines still offer a great potential of technological progress, thus contributing to the reduction of consumption and CO2 emissions while enhancing the car performances and its related driving pleasure.

In a cooperation the BMW Group and PSA Peugeot Citroën have joined forces in developing a new family of gasoline engines. These power units featuring the most advanced engine technology will be seen in future in models from Peugeot, Citroën, and future versions of MINI.

The new engine family is a significant move for both partners in fulfilling the self-commitment assumed by European car makers within their European Association (ACEA), promising to reduce fleet consumption and, as a result, CO₂ emissions to 140 g/km by the year 2008. The engines developed within the Project are able for the first time to elegantly solve the conflict of interests between demanding engine technologies and cost pressure in the small and compact car segment. The Project confirms that it is by all means economically possible to build fuel-efficient power units with innovative technologies also in the lower car segments.

In developing the concept for the new family of engines, the Project Team has opted for two variants in technology. Without making the slightest concession in terms of performance and refinement, the normal-aspiration power unit with fully variable valve drive as well as the turbocharged direct-injection engine will set a new standard in their displacement category in terms of both technology, dynamism, economy, and their overall package.

The engines created by this new joint venture come with numerous features carried over from BMW’s latest generation of straight-six gasoline power units. Examples are fully variable valve drive, the volume flow-controlled oil pump, single-belt drive of the engine’s ancillaries, individual coils, and composite camshafts.

At the same time a whole series of innovative solutions is being implemented for the first time in this class. These include direct gasoline injection for even more power, the twin-scroll exhaust gas turbocharger, the on-demand mechanical coolant pump, and the new tightening unit for the poly-V-drive belt.

The engine block as such meets all the demands and requirements of both partners in the joint venture. In terms of stiffness and acoustic features, the aluminium crankcase with its bedplate construction is absolutely unique and unparalleled. Optimisation of the crankdrive bearings and conversion of all mechanical valve drive transmission units to anti-friction rollers serve to provide the lowest level of frictional losses in this class.

Integration of numerous functions and ancillaries in the cylinder head as well as the crankcase make many of the usual add-on components superfluous, improve the engines’ acoustics, and reduce both engine weight and dimensions. Single-belt drive of the engine units also helps to make all dimensions very compact.

Controlled volume flow for even greater fuel economy.
On-demand oil supply delivers exactly the amount of engine oil required, no more and no less. Accordingly, the oil pump controlled as a function of volume flow reduces fuel consumption by up to 1 per cent. Together with the oil/water heat exchanger, the on-demand water pump serves to further reduce fuel consumption and emissions. This again saves drive power and warms up the engine more quickly, coolant only being circulated when the engine has reached its operating temperature.

Featuring innovative valve drive and 1.6 litres displacement, the normal-aspiration engine develops maximum output of 85 kW/115 bhp at 5,700 rpm. Engine torque reaches an impressive 140 Nm (103 lb-ft) at just 2,000 rpm, peaking at 160 Nm (118 lb-ft) at 4,250 rpm.

Without requiring a throttle butterfly, fully variable valve management controls engine output by infinite adjustment of valve lift and the intake valve opening times. This loss-free load management again reduces fuel consumption, cuts back exhaust emissions, and ensures superior engine response combined with enhanced motoring refinement. Apart from valve management, the overall control concept comprising a fully controlled oil pump and on-demand water pump as well as the optimisation of frictional losses makes the normal-aspiration engine the most efficient power unit in its entire segment.

Displacing 1.6 litres, the direct-injection high-performance gasoline engine with exhaust gas turbocharger and intercooler develops maximum output of 105 kW/143 bhp from 1.6 litres engine capacity at 5,500 rpm and maximum torque of 240 Nm/177 lb-ft from 1,400 rpm maintained consistently all the way to 4,000 rpm.

The cylinder head comes with conventional valve drive featuring two overhead camshafts, roller-type drag arms, and hydraulic valve play compensation.
Fully variable adjustment of the intake camshaft ensures optimum output and torque on low fuel and clean emissions.

This is the first engine in its class to feature a twin-scroll turbocharger separating the ducts of two cylinders at a time from one another in the exhaust gas manifold and turbocharger. This serves to build up the charge effect from a low speed of approximately 1,400 rpm, torque developing virtually just as fast as in a compressor engine.

Direct gasoline injection with common-rail technology, together with the turbocharger, is the main contributing factor ensuring the high level of engine output, superior fuel economy, outstanding refinement and exemplary emission management. The high-pressure valves inject fuel from the side directly into the combustion chamber at a pressure of up to 120 bar, ensuring a homogeneous fuel mixture within the chamber (l = 1.0).