Originally Posted by 05 LegacyGT
Gasoline engines sound better, smell better, are lighter, and usually rev higher. Those are really the only advantages though.
I guess itís different strokes for different folks on sound. I actually prefer the sound of a diesel. To me they sound ďbeefyĒ and powerful. The new ones in smaller vehicles sound essentially the same as a gasser anyways nowdays. The modded diesels usually sound like any other performance car, like the dragster in that video.
I donít notice much smell with either new gas or new diesel cars. Iím not really that into my carís exhaust smell anyway, but I guess itís important to other people.
The weight advantage used to be a big deal, but thatís becoming obsolete also. Since there are small diesels with aluminum blocks and other weight savings, some are about equal in weight to their gas counterparts, but they still produce a lot more torque.
I have to admit that I love the sound of a high revving engine. Thatís partially why I like my sport bikes. However, I think that the RPM advantage is also relative and a bit of a glass ceiling. While compression and stroke have some part in the RPM governing, I suspect that the two primary reasons that most diesels come out of the factory with lower redlines is that they are able to produce their power at such lower RPM that they just donít need a high redline and it would hurt efficiencyÖ and it would also start to break transmissions. The gearing takes the place of high revs. Besides, when you have several hundred pounds of torque on tap at 1700rpm, you donít really need to go to 7000rpm. With most turboíd gassers, the first 3000RPM is sort of wasted anyway while youíre waiting to get into the powerband. I donít even know any gasser turbo tuners that brag or even report much under 3K. Diesels can pretty much be in the power band right off of idle.
For evidence of the factory falsely low redline, Iíll use my truck as an example. Even with the enormous stroke and giant mass of spinning metal in my 5.9L Cummins, the only thing maintaining a factory 3000rpm redline was decreased fuelling for efficiency and to save the transmission. It only took a simple (commonly and safely done) modification to fuelling and valve springs to add another 1000rpm to redline, which also added enough high-end power to turn a stock transmission into a paperweight. Some of those engines that are used for pulling competitions or dragsters are set to run at 6000rpm or above (with crappy mpg) Pretty good for such a big engine, gas or diesel. It's a common and usually pretty simple mod for diesel owners to increase redline for big power gains to make their cars a lot more fun. It just takes the mpg way down.
Once again, I'm clearly biased, though.