The long anticipated merger of spark ignition gasoline and compression ignition diesel engine technologies picks up momentum with information released by Nissan in a document titled â€œNissan Green Program 2010â€ which puts the focus on CO2 reduction covering all aspects of the firm’s products and operations. Nissan says that for the foreseeable future, the internal combustion engine will continue to be the primary vehicle power source and will introduce a 77.5 mpg environmental poster child gasoline car as one part of its program . . .
Of particular interest to mass market auto interests is Nissan’s targeted launch from year 2010 of â€œgasoline engine technologies that will enhance fuel economy and at the same time reduce CO2 emissions to diesel engine levelsâ€. As a consequence of this, if US diesel fuel continues at the current 30-40 cents(US) higher price per gallon than regular grade gasoline(US north central states), vehicles with diesel and gasoline engines will have approximately equal fuel cost per mile..
Nissan says 4 cylinder gasoline engines will achieve the new fuel and CO2 levels by combining direct fuel injection (DI) with next generation turbocharger systems and that V6 and V8 gasoline engines will achieve the same result with DI combined with â€œVariable Valve Event and Lift Systems (VEL)â€, While compression ratios and exhaust gas recirculation (EGR) rates of these engines is not given, research on the HEDGE (high efficiency dilute gasoline engine) system at Southwest Research Institute for a consortium of firms including Nissan indicates that higher compression ratios and EGR rates can contribute to gasoline/diesel efficiency parity.. High HEDGE engine EGR rates are employed in what is called â€œdilute combustionâ€ that limits NOx formation and engine pumping losses…
VEL technology without DI gasoline, expected to cut CO2 10% during the interim, will be employed by Nissan starting in year 2007 in Japan and North America…
A dramatic use of high efficiency gasoline engine technology by Nissan will be a â€œ3-liter carâ€ (i.e., fuel consumption of 3-liters per 100 km or 77.5 mpg). A US Nissan representative, Fred Standish, declined to give an indication of the size of such a car except to say it will be â€œsmallâ€ and marketed first during 2010 in Japan…
In 2000 Volkswagen launched a limited production â€œ3-literâ€ 3-cylinder 1.2L diesel version of its small Polo car called the Lupo with 91 inch wheelbase. One of these cars came to the US for a few media members to test drive. This reporter tested the Lupo and can report it is a remarkably roomy car entirely able to get into the mix of vehicles including class 8 trucks at Interstate freeways speeds. . It was painted a very â€œloudâ€ light green that escaped nobody’s attention…
Another Nissan development is an engine system to be marketed in Brazil starting in 2009 that can operate with 100% ethanol. How such an engine can be started without
at least some gasoline mixed with the ethanol will be interesting when explained… One source speculates that very high energy ignition is a possible…
Further adding to car efficiency is Nissan’s already established Continuously Variable Transmission (CVT) with which one million Nissan cars will have been fitted by the end of 2007… Nissan says CVTs cut vehicle CO2 by up to 10%.
Nissan says it will launch six vehicles in Japan that feature a package of environmental technologies that will exceed 2010 Japanese regulated fuel economy standards by 20% and emit 75% less exhaust emissions than 2005 standards.
For markets with established acceptance of diesels, Nissan says it has developed diesel engines with advanced emissions controls the first of which will be a 2.0L engine for Europe in 2007 that meets the Euro four emissions standards. This will be followed by diesels that meet US Tier2 Bin5 emissions but diesel sizes, launch dates and price premiums are not given.
Other Nissan targets are to â€œaccelerate development of electric powerplant technologies with lower costs and increased performanceâ€: Elements of this plan include:
– Hybrid electric vehicles (HEV) will be launched in Japan and the US in year 2010.
– 100% electric vehicles will be launched in Japan during early part of the next decade.
– Plug hybrids that can be charged from both utility electric power and vehicle engine power will be developed on an accelerated basis.
– A new company will be formed for development, production and marketing of lithium-ion batteries…
– The Nissan fuel cell stack system will be employed for fuel cell vehicles in the early part of the next decade.
Separately, a GM spokesman for the firm’s powertrain operations says the combination of direct gasoline injection (DI) and a new 2-mode electrically managed dual planetary transmission with hybrid features will increase large passenger vehicle fuel efficiency by 45% compared with current engine and 6-speed automatic transmission technology. It will appear first in 2008 models. While the test method basis for claimed 45% mpg gain is not explained, GM powertrain hybrid engineer Mark Kosowski recently said during a media meeting that at steady highway speeds there is no significant efficiency difference between a 2-mode and conventional 6-speed automatic powered by the same engine. The 2-mode system fuel economy advantage when combined with DI engines apparently occurs during transient and city cycle operation.
The GM 2-mode system is being developed jointly with DaimlerChrysler and BMW.
Vehicle fuel efficiency is growing in importance in step with the escalating need for the US to reduce its dependence on imported oil and pressures from global warming concerns. Vehicle energy efficiency could be further optimized by reducing the mass of the average vehicle, however, motorist fear of smaller vehicles heightened by National Highway Traffic Safety Administration (NHTSA) high visibility car crash testing is a drag on conservation from vehicle downsizing. US oil companies have weighed in on the conservation issue by pointing out that motorists can cut fuel use 20% by avoiding hard acceleration and high speeds. Another voice for conservation is GM Vice Chairman Bob Lutz who told a media group last year that â€œGM could improve vehicle fuel economy if we could cater less to motorist demands for high performanceâ€..
About the author: Bob Brooks is a member of the Society of Automotive Engineers and a long time automotive technology journalist specializing in powertrains and energy.