07 2500hd tires

[Pikehunter]

I put Kelly Commercial (not made now) tires on my old 12v dually. Went from 15mpg to 17mpg unladen and 10mpg to 12mpg laden

[elkhornsun]

Going from 245 to 285 tires on my truck changed the gearing by 3.7%. Trucks come with 3.42 gears that are 25% higher than 3.73 gears and the 3.73 are 25% higher than the 4.10 gears and no one worries about it. Check the actual tire height of the tires and the difference will be about 1 inch. Under the load of a trailer the difference will be much less. With my truck and a full payload the 285 tires make my speedo 100% accurate which means that it was not accurate with the factory tires unless the truck was empty.

[Ray,IN]

Originally Posted by Pikehunter

Don't want to find a 265. Put the LT235/85R16 "E" tire on if you want better mileage.

Narrower tires do get better fuel mileage, wind resistance is the culprit. When empty, larger diameter tires may get better mileage, it all depends on the driver and the load. I would return to the OEM designated tire size. That tire size was determined from data on tire "footprint", then braking, acceleration, cornering, traction, etc.data are calculated into the equation. Any tire must have a specified weight per sq. in. of "footprint" for best handling characteristics. You will not buy a better tire size for your stock vehicle than what the factory design engineers designated.

[w2drfg]

I went out and bought 245 tires today so I will be watching fuel usage and mpg.
Sure looks funny going from 285s to 235s.

[w2drfg]

That is "from 285s to 245s" not 235s.

Sure looks funny going from 285s to 235s.[/QUOTE]

[Gordond]

I had 285 on my 02 2500 Hd ,went from Florida to Spokane ,on in to canada & back to Florida,was gonna put 265 on for same reason.Had an issue midway so made the switch. No notable difference in miliage or power.Have level kit Firstone air bags pull 30' 5er,both ride perfectly level.Wnet back to 285 when we got back to Florida.

[Clubhouse]

On my LMM I went from 245 to 285 then back to 265. 265 seems to be best balance of looks and performance for me. Each time I always purchased 10 ply "E" tires. For what it's worth I replaced my OEM wheels when I went to 285, 7.5" was a bit to narrow for the 285s and they are still a nice fit for the 265 I'm currently running.

IMO the OEM 245 GM puts on 2500 just look to small for the truck from a looks perspective -- but they certainly do offer the best all around performance for what the truck is intended for.

Any changes to OEM tire size affects not only on the final drive ratio, but also the computer as far as speedometer and fuel mileage calculation that needs to be taken into consideration.