SHOREHAM, UK - Conventional gasoline and diesel engines will continue to dominate the auto industry for at least another 20-30 years, according to engineers at Ricardo, the UK consultancy.
Hybrids will ensure a key role for internal combustion engines until 2040 and beyond.
After that, fuel-cell technology will begin to take over. Ultimately, all cars will be driven by electricity, said Neville Jackson, Ricardo's senior manager.
'But how we store it is another matter,' he said.
Ricardo, whose client list includes General Motors, Volkswagen, Volvo and Mercedes-Benz, expects gasoline engines to use 65 percent less fuel and produce barely detectable emissions by 2020.
Diesel fuel consumption will be halved over the same time span, said Jackson, with particulate emissions cut to gasoline-engine levels.
Several key hurdles have already been crossed on the way to the 2020 goal of emissions that are so low that they are hard to measure above background levels.
'It's 2005 and beyond that we're looking at now,' said Jackson.
European legislative limits for 2005 are still to be finalized. But Jackson said that neither the fuel-consumption barrier of three liters per 100km, nor the tough emissions thresholds proposed by environmentalists in the European Parliament in March, will present impossible challenges.
'It simply means you've got to look at the whole car and not just the engine,' he said.
Ricardo has mapped out a plan for advancing from today's cars - consuming around six liters per 100km - to the three-liter corporate fuel average that could become mandatory for 2010 or 2015.
A four-seater car weighing 700kg and using a 1.0-liter, three-cylinder, indirect-injection gasoline engine would consume four to five liters per 100km on the current EU driving cycle, said Jackson.
A direct-injection gasoline engine would cut fuel use by 20 percent. An intelligent transmission, such as a computer-shifted, seven-speed manual, would save a further 20-30 percent.
Diesels would already be there: a 1.5-liter, multi-valve, direct-injection engine with the seven-speed transmission should narrowly beat the three-liter target.
Key diesel developments will be electronic control of fuelling, turbo geometry, EGR - exhaust recycling - and, later, variable valve timing, said Jackson. For gasoline cars, direct-injection, stratified-charge engines will provide a huge jump in efficiency.
The main drawback for lean-burn engines is NOx emissions. But active zeolite catalysts, which use additional exhaust-line fuel injection, are already under development.
Still, Jackson believes that a more promising after-treatment technology is the gas plasma technique that exposes all pollutants to an electric field similar to that in a fluorescent light tube.
The big breakthrough will come when these non-thermal plasmas can be generated at low temperatures, at atmospheric pressures and with low energy inputs. Right now, said Jackson, plasma looks like the ultimate solution.