Hi sumac123,
Many guys do not understand hp/torque/rpm and/or gas vs diesel. You may or may not be one of them.
I'll use the latest Sprinter (188 hp) vs Chevrolet Express van (325 hp).
The work an engine will do is measured in horsepower Not torque, period. This is true whether it is a gas, 2 stroke, 4 stroke, diesel, rotary, electric..... To determine the horsepower, torque and rpm are measured then multiplied and divided by 5252.
In a drag race a Chevrolet Express van will leave a Sprinter in dust. Going up a mountain the Express Van even if the same weight as the Sprinter will leave the Sprinter behind because of the Very Significant Horsepower advantage.
But wait, there is one exception. IF the nountain road is very long And a significant 'enough' grade, the Sprinter will pass the Chevrolet. How can that be? The Express Van does not have the cooling system to allow 325 hp or even 188 hp to be used Indefinitely. The Express Van will have to slow down so that it does overheat. Could it have enough cooling system to pass the Sprinter? Sure, but it always comes down to the advantages vs disadvantages of doing so. There just are not that many mountain roads that long with a significant enough grade. The Express van can cruise all day at 85 mph with a normal operating temperature even going up hill. But if the grade up becomes significant enough, the Express will eventually need to slow down.
Me, I don't want a Sprinter after weighing the advantages vs disadvantages, but I would buy one if: I had to commute every day going up an interstate needing to slow down. I've driven my B in all of the US states west of the Mississippi and some of them east of the Mississippi maybe 500 hours or more. I have had to slow down and lost maybe a Total of 30 minutes on a couple of interstates.
Hope this helps.
Bud