If I have the following 2 vehicles:

Vehicle 1: Weighs 2000 pounds
Vehicle 2: Weighs 1000 pounds with a 1000 pound trailer

Which requires more engine power to move? Does the weight distrubution on the additonal axles of the trailer decrease the required force needed to move the vehicle?

A free christmas tree is riding on this (no pun intended). Thanks.

Skip the tree.

If you just add a trailer to the vehicle it adds mass, wind resistance, axle resistance and friction to turn the wheels. No matter how small you can engineer those resistances to be, if you add mass to the weight the engine must pull, you added work.

So: If you have a 1000 lb trailer to pull a 200 lb tree, you added 1200lb of work to the engine. If you strap the tee to the the truck you added 200lb of work to the engine.

You do the math...lol

Last edited:
DaveC426913
Gold Member
A 2000lb. vehicle will definitely be more efficient power-wise than a 1000lb. vehicle with a 1000lb. trailer for all sorts of practical reasons.

1000lb. vehicles are hard-pressed to pull double their weight, whereas a 2000lb. vehicle is designed to efficiently pull 2000lb.

rcgldr
Homework Helper
I think the original post is more about the number of axles. Assume two vehicles with the same mass, one with 2 axles, and one with 4 axles. Which one has more rotational friction?

One advantage of a 4 axle system is less force per contact patch on each tire, which should reduce the overall amount of rubber hysteresis. I'm not sure what it does for the overall rolling resistance.

Since the doubled up axles are in-line, there shouldn't be much difference in aerodynamic drag.