Tires: Roadtrek wandering, rim width, michelins

Question
QUESTION: My husband & I also own a 1996 Roadtrek, Dodge 350 maxivan. We just bought the unit and put new Michelins LTX M/S 245/75R16 tires, 80psi at the back and 55psi in the front. I noticed soon after installation that the van starting wandering, I just thought it was because of the wind that day, and we had just put water in the holding tank 2/3's full. Well our first trip out, anything over 60km/hr and the van was prone to wandering. It was especially bad when a transport passed us; the kinda bad that was "white knuckle". Is it possible that the new Michelins are the problem or part of a problem. I ask this because after doing some "blog" research the Michelins are getting bad ratings on this type of vehicle.

ANSWER: Darlene,

There are lots of reasons why vehicles wander.  So before we assign this to tires, you need to get the suspension looked at for worn components and have vehicle aligned.  Toe out will cause this wandering.

---------- FOLLOW-UP ----------

QUESTION: Hi Barry, since my last question we had new shocks put on and that cleared up the wandering about 70%, so the other question I have regarding the Roadtrek, as I had said, we bought it with Michelins LT245/75R16's, they were the originals, so we put new Michelins LT245/75R16's on, but the placard on the drivers door and the spare are Michelins LT225/75R16's. Because the unit is tall and wind sensitive, do you think that this unit would handlle better with the 225's? and are these's 245's causing us problems?

thanks.


Answer
Darlene,

Did you get the vehicle aligned?  As I indicated earlier, toe out will cause wandering - and you need to eliminate that as well.

But to answer your question.

If the vehicle originally came with LT225/75R16's then it also likely came with 6" wide rims.  LT245/75R16's have an allowable rim width range of 6 1/2" to 8". And guess what?  Using a rim that is too narrow makes the tread face arch more and that could cause the vehicle to wander.

But before you go very fair, make sure the basics are done:  Alignment, and check that the rims are indeed 6" wide.  Some vehicle conversion companies also change rims.  If you don't check this you could spend a lot of money with very little to show for it.