Hetex Engines-What About Diesels?

The only available alternative to the Otto engine has been Rudolph Diesel's engine which he described in 1893. In countries where fuel is costly, a rapid shift is taking place towards more frugal Diesel engines. In Europe, almost 75% of new cars are being purchased with Diesel power. And in the US where virtually all automobile engines are of the Otto four-stroke gasoline powered type, a switchover in purchasing seems to begin whenever gasoline exceeds about $2 per gallon in 2002 values. A Diesel is about 37% efficient in vehicular use and large stationary Diesels, when operating at optimum RPM and load, now attain up to 54%.

Diesel power for cars has its disadvantages. The engines are noisy at idle, limited to half the range of RPM and they are roughly twice the weight of an Otto engine. They are also about twice as expensive as an Otto engine to purchase ($2,000 extra for a new car), and twice as expensive to service and maintain.