Originally Posted by N147JK
I have an E250 with the same 8600 GVWR. I wonder how the GVWR is arrived at (springs, axle, brakes, a combination?) and why the same sub-model came off the assembly line with different ratings. Were they specifically ordered by customers that way?
In recent years (from when the E-150's went 8 bolt lugs) I know the GVWR went up on those. They may have larger brakes than the older ones as well.
The frames of the 150/250/350 have different cross sections (section modulus) I would imagine that has some bearing as well.
If CarringB stops by I imagine he has more insight on this.....