Fiat Auto has sold its patent on a new system of direct diesel fuel injection to Robert Bosch GmbH, the Stuttgart-based supplier.One condition of Fiat's sale was that the system appear first in a Fia t auto.
It will be commercially available in about 1998, says Mario Petronio, Fiat's technical director in charge of engine projects. Petronio claims that the new system is far quieter than other direct injection systems. It wil l be a great step forward, as big a step as the one from a carburetor to existing direct injection systems. he system uses a unit injection process. Each injector has its own electric pump instead of a central pump feeding all injectors.The system avoids the very high peak pressure normal in direct injection, which causes most of the noise, says Petronio. Emission control is much more effective also, he adds. From a cold start, you still recognize it as a diesel, but once warmed up, at autostrada speeds, the noise drops to normal. It is very impressive. Fiat'sMarea and Marea Weekend, the sedan and station wagon versions of the Fiat Brava/Bravo hatchback family cars, use indirect injection in their diesel versions. We believe in direct injection diesels, says Petronio. We were the first to launch a car with direct injection engine. At the same time we know that direct injection has some problems. Disadvantages include noise, which is still worse than indirect injection. Fiat is the leader in making direct diesel injection engines for cars. It launched a 1.9-liter direct injection car engine for the Croma in spring 1988, five month s ahead of Austin Rover's Montego direct injection. Audi's first direct injection did not appear until summer 1991.Mercedes-Benz entered the segment by launching the current E-class in spring last year. General Motors Europe re cently announced its direct injection diesel.PSA, a longtime maker of indirect injection car diesels, is scheduled to launch its first direct injection car engine next spring.