Tire size question

JIMNLIN wrote:
A LT265/75-17 has a 8.5" wide tread. Load carrying tires work better on a truck if the tires tread width matches the wheels width. Racer types can mess with that ratio to achieve different results which load carrying isn't one of them.
If the truck is used a tow machine I would stick with the 245/75 tires as being a smaller diameter. I found I get more towing performance especially with a small block gas engine with a smaller diameter tire.
Also GM was bad about using 6.5" wide wheels on 2500 size trucks. A LT265/75-17 E has a 7"- 8.5" wheel width requirement vs a 6.5"- 7.5" for the LT245/75-17 E tire.

x2: Correct. Tread width should match rim width for best results.

^^^^ What Jim said. GM OEM wheels are 6.5 wide, and tire shops should not be mounting 265's on them, however I see it a lot. Where is Cal to explain this in detail? My 2001.5 Ram came with 265's on 8 or 8 1/4" rims. Chris

A LT265/75-17 has a 8.5" wide tread. Load carrying tires work better on a truck if the tires tread width matches the wheels width. Racer types can mess with that ratio to achieve different results which load carrying isn't one of them.
If the truck is used a tow machine I would stick with the 245/75 tires as being a smaller diameter. I found I get more towing performance especially with a small block gas engine with a smaller diameter tire.
Also GM was bad about using 6.5" wide wheels on 2500 size trucks. A LT265/75-17 E has a 7"- 8.5" wheel width requirement vs a 6.5"- 7.5" for the LT245/75-17 E tire.

I buy whatever is cheaper. Often that means 235/85 R16.

Wouldn't worry about the speedo if you upsize. The 245 pizza cutters will allow the truck to pull just a little better than the taller tires, but not alot.

I have always run one size larger tires on my trucks. The speedometer error isn't enough to worry about. In fact, on a couple of the trucks I have owned over the years, the larger tires CORRECTED the existing speedometer error (according to the Garmin).
If it was my truck, I would stay with the 265/75-16E tires.

I'd keep the 265 tires. That's what came stock on the 3500 SRW trucks. I always thought the 245s looked a little small on a 2500.

If that truck would of had the Z71 package as an option it would of had 265-75-16 on it OEM. If you had access to a GM tech with the programmer adjusting the speedo between tire sizes is a push of a button. A GM dealer will set you back about $100 to do that if it bothers you.

I run the bigger tires with no problems on an 08 2500. The speedometer is off by 2 mph and my miles/gal on the computer is off by about 1 mpg vs my hand calculations, but the ride seems better.

Biggest that fit and don't scrape the wheel wells has always been my plan....