is there a "formula" for weight of coach to engine size for a diesel pusher/puller?

I know there are a lot of RV's out there that are under powered. Just curious.
Tere

The price seems to be more important than adequate power - I saw a 36' SOB at the tire store with a Cummins 5.9L.

Keep in mind that comparing gaso engines to diesel is apples-to-oranges. HP is basically torque X RPM. Gassers' max HP is at an RPM much higher than diesels', and the latter is typically rated to run at max output indefinitely.

Acceleration is a function of torque, and the diesel generally wins with low-RPM torque.

quote:

Originally posted by Jim and Tere:
is there a "formula" for weight of coach to engine size for a diesel pusher/puller?

I have seen figures, but they mention only HP and weight.

If I were looking at a DP, I would look at weight and torque. Actually, gassers, too. My 502 is a torque monster, but has only 325 or so hp.

For example, there are 5.9 Cummins engines with the same hp as some 8.3 engines. However, the 8.3 has much, much more torque, making it a better RV hill climber.

To a lesser degree, the same applies to gassers. A 350 can have the same hp as a 454, but the 454 has more torque and is a better MH engine. Even if a 350 and a 454 have the same torque, the 350 probably has it at a higher rpm point, making it less useful for an RV.