Honda Motor Co has unveiled a range of next-generation engine technologies as part of its global initiative to reduce CO2 emissions, including a next-generation diesel engine, an Advanced VTEC engine, a new fuel-cell vehicle and a Flexible Fuel Vehicle (FFV) capable of running on ethanol.

Advanced VTEC engine

Honda has further advanced its VTEC (Variable Valve Timing and Lift Electronic Control System) technology with the development of the Advanced VTEC engine, which achieves high performance along with outstanding fuel economy and lower emissions. The new engine combines continuously variable valve lift and timing control with the continuously variable phase control of VTC (Variable Timing Control). Honda plans to release a production vehicle equipped with the new engine within three years.

This new system permits optimum control over intake valve lift and phase in response to driving conditions, achieving improved charging efficiency for a significant increase in torque at all engine speeds. Under low to medium load levels, the valves are set for low lift and early closure to reduce pumping losses and improve fuel economy.

In combination with optimised intake components, these advances in control technology result in world-class dynamic performance along with approximately 13%* improvement in fuel economy. The new engine is also exceptionally clean, with exhaust emissions that meet both U.S. Environmental Protection Agency LEV2-ULEV regulations and Japanese Ministry of Land, Infrastructure and Transport requirements for Low-Emission Vehicles, with emission levels 75% lower than those required by the 2005 standards (based on Honda calculations).

* Engine only, as compared to production 2.4-litre i-VTEC engine (Honda calculations)

Flexible fuel vehicle (FFV)

Honda has developed a new flexible fuel vehicle (FFV) system that enables petrol engine-based power plants to operate on either 100% ethanol or a wide range of ethanol-petrol fuel mixtures.

Up to now, variations in the ratio of ethanol-to-petrol have affected low-temperature startup performance and caused variations in air-fuel ratio and engine output. This has made it a challenge to maintain stable dynamic performance, fuel economy and emissions levels. The new Honda system adapts to different ethanol-to-petrol ratios by estimating the concentration of ethanol in the ethanol-petrol mix in the fuel tank based on measurements of exhaust gas concentration in the vehicle’s exhaust system. This provides the flexibility to adapt to ethanol-to-petrol ratios of between 20% and 100%, while achieving outstanding fuel economy and dynamic performance on a par with a 100% petrol-powered vehicle. In addition, a cold-start system utilising a secondary fuel tank ensures reliable starts even at low ambient temperatures.

Bioethanol fuel, as used in Brazil and other countries, is made from plant sources such as sugar cane. Because plants absorb CO2 via photosynthesis, the amount of CO2 released into the atmosphere from burning bioethanol fuel does not increase atmospheric CO2. This makes bioethanol fuel an effective means to combat global warming as well as an alternative to petroleum.

In late 2006, Honda plans to begin sales of FFVs in Brazil, where bio-ethanol has gained in popularity.

Sadly, Honda Australia currently has no plans to introduce the Honda flexible fuel vehicle into Australia.

Fuel cell powered vehicle

Honda Motor Co has conducted a demonstration drive of the next-generation FCX Concept fuel cell vehicle. The FCX Concept features a newly developed compact, high-efficiency Honda FC Stack as well as a low-floor, low-riding, short-nose body. It offers a comfortably large cabin and futuristic styling along with significant improvements in power output and environmental performance.

To meet Honda objectives for significant gains in both environmental and driving performance, the FCX Concept is equipped with a V Flow1 fuel cell platform consisting of a compact, high-efficiency fuel cell stack arranged in an innovative centre-tunnel layout. This has allowed designers to provide an elegant, low-riding, sedan form that would have been difficult to achieve in a conventional fuel cell vehicle. This new fuel cell stack is 20% smaller and 30% lighter than the current FCX FC Stack, yet its power output is 14 kW greater. The drive motor has been positioned coaxially with the gearbox for a more compact design, with output increased by 15 kW. Overall, the power plant is about 180 kg lighter than that of the current FCX and about 40% smaller in volume. The result is improved energy efficiency and performance along with a more spacious interior.

While with previous fuel cell stacks the hydrogen and the water formed in electricity generation flowed horizontally, the new FCX Concept features vertical-flow design. This allows gravity to assist in discharging the water that is produced, resulting in a major improvement in water drainage, key to high-efficiency fuel stack performance. The result is stable power generation under a broad range of conditions, and higher output from a smaller package. Low-temperature startup has also been significantly improved, enabling cold-weather starts at temperatures 10˚C lower than the current FCX — as low as minus 30˚C.

Limited marketing of a totally new fuel cell vehicle based on this concept model is to begin in 2008 in Japan and the U.S.

Next-generation diesel engine

Honda Motor Co., Ltd., announced it has developed a next-generation diesel engine that reduces exhaust gas emissions to a level equal to a petrol engine. Honda’s next-generation diesel engine employs a revolutionary NOx catalytic converter that enables a great reduction in NOx emissions sufficient to meet stringent U.S. Environmental Protection Agency (EPA) Tier II Bin 5 emissions requirements (based on Honda’s internal calculations). This catalytic converter features the world’s first innovative system using the reductive reaction of ammonia generated within the catalytic converter to “detoxify” nitrogen oxide (NOx) by turning it into harmless nitrogen (N2).

The new catalytic converter utilises a two-layer structure: one layer adsorbs NOx from the exhaust gas and converts a portion of it into ammonia, while the other layer adsorbs the resulting ammonia, and uses it later in a reaction that converts the remaining NOx in the exhaust into nitrogen (N2). Ammonia is a highly effective reagent for reducing NOx into N2 in an oxygen-rich, lean-burn atmosphere. This ability to generate and store ammonia within the catalytic converter has enabled Honda to create a compact, lightweight NOx reduction system for diesel engines. The system also features enhanced NOx reduction performance at 200–300ºC, the main temperature range of diesel engines.

Honda designed the catalytic converter for use with its 2.2 i-CTDi diesel engine, which has earned widespread praise for quiet, clean operation and dynamic performance since its introduction in 2003 on the European Accord model. By further advancing combustion control, the 2.2 i-CTDi delivers cleaner exhaust to the NOx catalytic converter. Honda achieved this by optimising the combustion chamber configuration, reducing fuel injection time with a 2,000-bar common rail injection system and boosting the efficiency of the EGR (exhaust gas recirculation) system. Thanks to these improvements, Honda has reduced the amount of NOx and soot normally found in engine exhaust, while increasing power output.

Along with developing superior technology for cleaning exhaust gas, Honda plans to address other technical challenges in developing clean diesel engines, such as handling diesel fuels with different cetane numbers and meeting U.S. On-Board Diagnostic System requirements.

Petrol engines presently employ three-way catalytic converters that offer NOx reduction rates as high as 99%, but this performance is possible only at the stoichiometric air-fuel ratio. In the oxygen-rich environment of a lean-burn diesel engine, three-way catalytic converters only reduce NOx levels by approximately 10%. Honda’s new catalytic converter efficiently reduces NOx in a lean-burn atmosphere, enabling diesel engines to rival petrol engines in cleanliness. The compact system is also easy to install in passenger vehicles.

As an auxiliary power source, the FCX Concept carries a compact, high-efficiency lithium ion battery, contributing to increased power output and a more compact power plant. These efficiency improvements to major power plant components give the vehicle a travel range approximately 30% greater than the current FCX. The vehicle is also highly efficient, with an energy efficiency of around 60%—approximately three times that of a petrol-engine vehicle, twice that of a hybrid vehicle, and 10% better than the current FCX.

Other features include seat upholstery and door linings made from Honda Bio Fabric, a plant-based material that offers outstanding durability and resistance to sunlight damage. Other improvements such as Shift-by-Wire and a newly designed instrument panel with easy-to-read display of hydrogen fuel consumption facilitate improved ease of operation.

The new fuel cell vehicle currently under development for release in 2008, will feature the principle technologies of the FCX Concept to achieve a new dimension in environmentally friendly driving pleasure not found with petrol-engine vehicles.