Pickup truck tow vehicle stability tests

transamz9 wrote:
So what everyone is saying is that a 1999 DRW 3500 is going to be way more stable than a 2015 SRW 3500? DREAM ON! Two extra tires don't make the difference people. I drive them both daily. I have pull the same loads with both and there ain't as much difference if they are both with-in their capacities. When you go from a SRW truck to a 5 year newer DRW truck then yes it's going to seem night and day difference.

Although the the wider stance helps slightly in stability, the fact that the axle is sprung to the frame at the same width between SRW and DRW creating a pivot point tells me this is not the answer. I feel it has to do with the spring rates of the leaf pack and the torsion strength of the stabilizer bars that gives the DRW a more steady feel over the SRW. Unless side winds were so great that lateral traction was compromised with a SRW, I cannot see how a wider footprint will help.

Matching the track of the tow vehicle to the trailer is important on worn highways where the wheels will hunt for the depressions, but now we're talking about matching vehicle width to road conditions rather than stability differences between vehicles.

I will wag that if you took identical trucks with nothing different between the two other than a SRW and DRW rear axle, you would be hard pressed to differentiate between the two. If you have a DRW, an easy test to prove this is to remove the the outside wheels and run with only the inners.