Thanks for catching me. I must have found a euro source for the info because all of the US Spec models I can find now clearly confirm 8 valves. Now I'm curious why the Euros get twice as many valves as we do?PlaneCrazy said:Only one minor quibble with the article, the N. American spec 2.0 TDI is an 8-valve engine, not a 16 valve unit like in Europe.
But otherwise, interesting write-up.
Thx...anwsered several of my questions. :thumbup:PlaneCrazy said:I believe it is the sound of the actual combustion. Earlier indirect injection engines had a combustion pre-chamber to attenuate the sound of the combustion. Direct-injection engines do not have these pre-chambers so that they technically should be noisier. However with more precise combustion control through computer-controlled EFI, and with good soundproofing, they don't intrude like older diesels.
Remember that each power stroke in a diesel generates more force than in a gas engine. A gas engine produces power by many small explosions, a diesel produces power by fewer but stronger explosions. However as diesels cannot rev as fast as gas engines (due to combustion characteristics), overall horsepower is less, but usually torque is signficantly higher at lower RPM (HP = Torque x RPM)
It stands to reason that a more powerful explosion, will cause more noise.
'05 Passat GLS TDI