Quote:
Originally Posted by spinzero
I hear what you're saying, gas engine is ultimately the sexier choice for sure. But when in comes down to fuel economy, I think the advantage of diesel over gas engine is more than just skin deep, as the difference in compression ratio fundamentally sets them apart. Even with infinitely advanced knock control, the best a gas engine can do is to approach that limit of detonation ever closer. A diesel engine, on the other hand, by its nature operates with much higher CR. And with modern diesels pumping out similar HP/Liter to top class gas engines and gobs more torque, I think they are quite attractive.
But then again I didn't grow up around diesels, so they are kinna mystical to me. :biggrin:
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Actually, the main difference is that the carnot cycle (gasoline engine) has a theoretical efficiency of 37% and the diesel cycle 42% (So just 5% gap in efficiency). So if the mileage of car was measured in miles per Kjoules, the difference would be less than what it is in mpg. 1 gallon of diesel contains more energy than 1 gallon of gas.
I am a little bit fundamentalist on that. Diesel (especially 6 cyl) can be good on some kind of cars, but not on a sport coupe.
I also practice cycling and I can tell you that there is really a difference when I train around cars in US and in France. Diesel exhaust gas really sucks with the particules, but the diesels you will get in US will be the cleanests, and you will get 6 cylinders, so not so bad. But even a 6 cylinders diesel vibrates at idle and what is really diferent is how the engine behaves, the torque just decreases after 2500 rpm which make the sensations really differents.