Vulcaneer wrote:
Another important thing is...at what RPM.
"At what RPM" can be taken care of completely by overall vehicle gearing. That doesn't mean gearing is always correct for a gasser to provide one with the drive axle torque needed at one's desired speed. However, "correct" gasser gearing can convert it's horsepower to - if it's horsepower is the same as any diesel it's being compared to - the same pulling power as the diesel. That's why I mentioned gearing in my earlier comments above.
Vulcaneer wrote:
Another important thing is...at what RPM. If it makes the Torque (and HP) at a much lower RPM, then the comfort of towing is much better. And your seat of the pants feeling is much better.
Your above words of "comfort" and "seat of the pants feeling" is exactly what I had in mind when I used the word "preference" in my earlier comments above.
For instance in my case: I get a great kick in the seat of the pants from my RV's V10 engine when I press down the gas pedal after the tranny shifts a gear to increase the V10's RPM so as to tap more horsepower. This is the same effect a diesel of equivalent horsepower will produce - just without the gear change.
My "preference" is a high RPM engine - not a thumping/rumbling beast. I much preference the spirited whine of the V10 when pulling up grades and accelerating. Nowadays high RPM engines that are also reliable can be mass produced so as to last a long time ... Ford's truck V10 is an example. For several decades this was not the case - so low RPM diesels became popular all over the world for three reasons - reliably back then being one of them. The other two reasons probably being kick in the seat of the pants without gear changes and ease of production of diesel fuel all over the world as compared to the processes required for gasoline.