Scientists in Sweden have modified a diesel engine to work with gasoline, an adjustment they say could significantly reduce emissions and fuel consumption for vehicles on the road. The researchers at Lund University have taken a common refuelling mistake and turned it into an asset that might ultimately help truck companies meet stringent emissions reduction targets. Jim Drury saw it in action.
UPSOT: ENGINE Professor Bengt Johansson says his modified diesel engine could help truck drivers vastly improve their fuel efficiency and curb their emissions. UPSOT: ENGINE While it may seem counter-intuitive, Johansson has adapted the engine to run on gasoline. SOUNDBITE (English) BENGT JOHANNSON, PROFESSOR OF COMBUSTION ENGINES AT LUND UNIVERSITY, SAYING: "It is pretty much the same engine, same fuel tank. You need to fill up with a different fuel but that's it. And it's kind of done already by mistake by hundreds of thousands of people every year filling up their diesel cars with petrol, so it's not very good to do it if you don't know how to do it.....but if you know how to do it you get significant benefits, lower fuel consumption, and also lower emissions." Key to the work by Johansson, and Lund University colleague Professor Per Tunestal, is an ignition delay of nanoseconds. SOUNDBITE (English) PER TUNESTAL, PROFESSOR OF COMBUSTION ENGINES AT LUND UNIVERSITY, SAYING: "The ignition delay allows the fuel and air to mix well enough before the combustion starts and by doing so you can avoid very high temperatures where you get nitric oxide formation and you can also avoid very fuel rich zones where you get a lot of production of soot." They call it their partially premixed combustion process - PPC for short. And in laboratory tests this delay between fuel injection and combustion has produced dramatic results. SOUNDBITE (English) PER TUNESTAL, PROFESSOR OF COMBUSTION ENGINES AT LUND UNIVERSITY, SAYING: "Compared to a normal diesel process we're talking about orders of magnitude, so a reduction by somewhere around 95 to almost 100 percent of both the nitric oxide emissions and also of the soot emissions." Tunestal says their methods could revolutionise the trucking industry, by keeping engines so clean they won't need catalytic converters and improving fuel efficiency by almost fifty percent. PPC could even be adapted to future car diesel engines, although the Lund team says it could take another decade before the technology hits the road.