Tahoe vs Suburban

JBarca wrote:
Hi Guys,

I used to have a 2002 K1500 Tahoe and replaced it with a 2003 K2500 Suburban. Both where good trucks, the Burb even had rear wheel steering (Quadrasteer). I sure miss that truck, we just grew out of the towing capacity. I have measured both and here is the differences concerning wheel base and rear overhang.

If I put my Reese HP WD shank in the truck receiver I had this:

2002 K1500 Tahoe:
- 116" wheelbase
- 58" rear overhang (rear axle to tow ball)

2003 K2500 Suburban:
- 130" wheelbase
- 65" rear overhang

One would think the shorter rear overhang would give the Tahoe an advantage, however the math says no.

A rule of thumb for towing stability is the rear overhang is no more than 1/2 the wheelbase. So lets see.

Tahoe: 116/58 = 2 Or the rear overhang is exactly half the WB

Suburban: 130/65 = 2 Or the rear overhang is exactly half the WB

so the ratio of rear overhang to WB is the same.

Now lets look at the force moments if we apply a 500# side load agasint the tow ball. What is the force of resistance at the front axle?

(Summating forces around the rear axle)

Tahoe: 500# x 58" = Y# x 116" Solving for Y, 250# seen at the front axle.

Suburban: 500# x 65" = Y# x 130" Solving for Y, 250# seen at the front axle.

According to the math, as far as WB and rear overhang there is no difference in stability between the Hoe and the Burb.

If the Burb with 130" WB had a 58" rear overhang, it would be better.

From what I have found, tire sidewalls flex will have a significant effect on towing stability, even in the 2500 Burb. Been there and felt/proved that. The wrong tires, LT E load range or not can make or break the stability of a tow rig. It was more of a factor then the rear overhang concern in this case.

Hope this helps

John

I completely agree with your data and calculations, well done, I respectfully disagree with your conclusion of them having the same stability. When the front tires sees those 250 lbs of side load, the sidewalls act a bit like springs and deflect. Given that both vehicles deflect the same amount sideways at both the front and rear wheels, the longer wheelbase one will be traveling closer to its original course than the shorter one. That is more stable in my book. I calculated over a 14% difference in angle of travel between the two using 1/2" of lateral movement at rear and 1" at the front. ( angle = arctan(1.5 / wheelbase) ). For a simple demonstration, set a ruler and a yardstick down and then move one end of each of them sideways by an inch. That smaller one will be pointing more sideways. While the difference is more subtle with the vehicles, it's still real.

This sideways yaw angle is one of the things that stiffer sidewalls help to minimize, regardless of the vehicle.