Well most folks think HP HP HP (Horse power) And like TIM Taylor (TV Show: Home Improvement) MORE POWER.....
Actually it is torque that gets you moving,, HP keeps you moving.
Diesels generally have more torque at low RPM However a good transmission (Allison) can make up for it.
Now: Another thing is this, Torque is aq function of HP to some extent so if you have say a 450 HP engine, and the guy beside you has a nearly same weight but only 350 HP.. Yes. His will be sluggish, compasred to yours
But if you put a 425 HP Diesel against a 425 HP gas... Well I can't tell you who will finish the quarter mile first.
I can tell you the fastest RV in the USA is gas.. but it's not .. exactly.. Stock... It isd a vintage GM that has been er. slightly modified. You don't want to know the Horse Power rating (or perhaps you do) on that big engine.