04/07/2008 05:17. The crucial difference between the two power units is that the
diesel achieves combustion through compressing its fuel/air
mixture, whereas the petrol engine, which uses lower combustion
pressures, needs a spark plug to ignite its fuel/air combustion
charge. Engineers have contemplating the combining of both
technologies for some years now and most big car firms are working
on their own version of a petrol engine that runs as a
throttle-less diesel at certain periods; most notably Volkswagen,
General Motors and Mercedes. It was Merc that got the best name,
however.
We had a chance to drive the F700's Diesotto engine in a test mule,
a long-wheelbase, V8 Mercedes S-class fitted with the experimental
engine. It runs on regulation unleaded petrol and its power and
torque figures give the... //
Telegraph.co.uk 