The High Speed Direct Injection Diesel for Passenger Cars

It is shown that the potential benefit of a direct injection system is a 10% gain in fuel economy compared with that obtained from an indirect injection system. A realistic consideration of the features of various diesel combustion systems shows why the indirect injection approach is universally applied to diesel passenger cars today.

A production indirect injection diesel of 1.8ℓ total capacity was converted to direct injection form and test bed and vehicle performances obtained. The constraints imposed by the need for compatibility with existing engine ranges and the use of low cost, currently available injection equipment caused reductions in smoke limited power although gains in fuel consumption at equivalent engine load were achieved.

A viable direct injection passenger car diesel requires more advanced injection equipment and boosting.