Trucks/Tractor design?

Farm tractors don't have 5th wheels and farm tractors cannot maintain minimum hwy speed limits. Bad thing about your idea is that taking off the weight off the drive axles gives a road tractor that tail wagging the dog effect. If possible, you want the weight on the tandems and drives to be about the same in severe weather.

 

The drives are like their name says.......driven.
So the more weight on then,the more downforce you have.
And downforce is what you need to put power down on the roadsurface.
But you have to stay within the working area your tires were designed for.
Overload will cause extra wear.
So like most things in life it is finding the right compromise which is important.

Hope this helps you.

 

It's a combination of both... Take tongue weight off your implement in the field, and I bet you loose traction... Same reason you run ballast on the front/rear for different implements, to gain traction. A big rig is the same way... You need ballast (pin weight) to improve traction/stability. You are carrying some of the weight, and pulling the rest.

 

Most trucks are designed to pull the normal maximum allowed 80,000 lbs GCWR but states also have axle weight limits . Here are the limits per state . http://www.aitaonline.com/Info/Road/Weight Size Limits.html