35 inch verses 33 inch tires

[tch777]

Hi guys I am running the BFG AT in 33x12.5x15 size.
When these are worn out I am going to go to 35s.

Do the 35's have stiffer sidewalls?

Reason I ask as I feel the 33s are too flexy and I am close to just going with 16 inch rims so I can get a load range D tire with stiffer sidewalls.

Our Suburban is mostly used on the asphalt or gravel roads and I would rather have more stability to eliminate some of the sway than flexy sidewalls.

Thanks

Tim

 

[The Butcher]

Tim,
A load range D, and a 16" rim should help, but make sure it is the tire sidewall that is causing the sway. Are your tires aired up to the correct psi for the load you are carrying? I know it sounds simple, but I'm just trying to help eliminate things.

The load range D tire should help, but you are still adding an inch more total sidewall (thus more potential lateral movement) even after going up to 16" wheels. If the truck feels "squirmy" when you are going down the road (ie, the a$$ shifts side to side for no apparent reason) then you probably have a sidewall issue. However, if it seems like the body wants to "roll" then you might want to look at your suspension more closely. If you have factory springs, your leaf packs could be shot. At this point they are 14 years old, and a suburban is not exactly a lite truck to sit on springs for that many years. A sway bar (if not already equipped with one) might be something else to look into. Since you are replacing the tire anyway, I guess you will be able to figure out if that is the problem. If it doesn't get fixed that way, look into getting new springs, or a sway bar.

 

[4xcrazy]

Mine sways real bad too, i believe i have found it to be the bushings and rear springs causing this, i even went with stiffer shocks and still running the quad shock setup on the front, even AFTER i installed the 4"lift kit, it still does it, though not as bad as was when stock.

i am still running the sway bar too.

tires size now is 33x12.50/15, have run 267/75r16, and originally had 31/10.50/15

swayed with all of them

and i am of course assuming when you refer to "swaying" the side to side rocking while driving down the road?

 

[trailblazr81]

Is there a reason you want to go to a bigger tire or is it just your having problems with your 33's? Because you'll probly want to add a bit more lift to clear the tires as well as you'll be loosing acceleration and braking from the larger/heavier tire. If all these areas will be addressed then I think a 16 or 16.5 wheel and load range D tires should do the trick. I've heard of Super Duty's with large tires still being able to tow/haul heavy loads.

 

[tch777]

I have the factory sway bar on front and an aftermarket sway bar on the rear. I run the tires at the max inflation on the sidewall of 35 PSI.

I am going to put in a 4 inch lift and go to the 35's cause the Wife likes big trucks, she doesn't want no wussy truck.

I can feel and see the sidewall flex. There is sway from the old springs too.
I think the springs might be the biggest factor. I put on stiffer pro comp shocks and they help a little.

I am installing slotted rotors and high performance pads in the front next week. And next year I will put in rear disk brakes. And then possibly hyroboost too.

Thanks for the replies.

Tim

 

[u2slow]

IMO sidewall design varies significantly - even within the same load rating. Check the # of sidewall plies and composition.

I have some Michelin LTXs and BFG Muds than have downright flimsy sidewalls compared to the Toyo M55s and Bridgestone Duellers.