245's to 265's, what will be affected?

[Fuddrucker]

Sorry guys if this is a beaten subject. I did a search, but found way too many "tire" and "gear ratio" postings that did not really answer my questions.

 

I am going to get a new set of BFG A/T tires. Right now I still have the stock 245's and want to go with 265's. What will this affect? Will my 4.10 ratio be lowered much? Will I loose a lot of HP? Anyone know how much taller the 265's are compared to 245's. Also, will I gain anything like better handling, braking just by going to 265's not the brand? Lots of ?'s I know. I do tow a 22ft. trailer that weighs about 8500lbs. ANY and ALL info will be greatly apreciated!!

 

Thanks in advance!

[BishopZ71]

The only thing that was affected when I put it on my old truck was look. Made it look better than the 245's. Go and do it.

[Peter_C]

I did tons of research on just the subject you are speaking of. I have gone from 245's to 265's on two K2500 Suburbans now. The first time I went with BFG KO AT's which are only D load range. They did not work very well as our trucks require an E loan range. That is one of the main reasons I went with the advice of the guys pulling heavy 5th wheels and bought Bridgestone Revo's in an E load range. As to the tire size change affecting the ABS and PCM it will. A local dealer can reprogram the PCM for the 265's. I went with the Wester's PCM that took care of that and got me very noticeble HP and torque gains. Many people say they get better milage with the Wester's also. It would be a definite plus for towing your heavy trailer.

 

Here is a discussion that took place on the board recently Tire Survey

[soccermom]

I recently added 265/75/LRE revos to my 2500HD. I haven't noticed any change in shift points/ABS operation/handling but plan on a dealer PCM re-flash or Westers to eventually get everthing straight. Go to dakota-truck.net, they have a tire calculator there that will answer your dimension and gearing questions. The Revos are impressive tires, lots of grip and suprisingly quiet. The 265 tires also look much better than the 245s, not as cool as the 285s but for the heavy snow I encounter I prefer a narrower tire.

[GoneYukon]

According to this Tire Calculator the difference when going from 245's to 265's is only .5% @ 60 mph or 3 mpg. So when the speedo reads 60 you're going 63.

[ManyCamaroz]

My Yukon had 265's on it when I bought it. I checked the mph against a GPS and it was correct. Don't know if the previous owner had it reflashed but very seriously doubt it. I noticed a slight rub on the lower control arms from turning to sharp but nothing to catch or cut on. I just had a new set of tires puton and went the same way.

[Fuddrucker]

Thanks for the info everyone.

 

The calculators worked great and gave me all the answers I was looking for.

[gmcjoe]

Since you already have 4.10 gear setup, you should be fine. Going with a taller tire will lower that number, effectively giving you a 'lower' gear ratio.

 

I noticed a huge difference in performance when I went from 265s to 285s on my 2000 GMC w/ 3.73 gears.

 

They will look much better on your truck though