difference between P245 and P265

[jaslo]

Just wondering if there is that much of a size difference between P245 and P265, because my truck came with P245 but I exchanged them for P265, should I have had the computer reprogrammed or is it even worth doing. I dont think it would make that much difference. Any opinions would greatly be appreciated.

[chevy4x4trucks]

It's not worth paying the money.  For starters cops will give you leway of 5 mph.

 

P245 75 R16 = 30.5 x 9.6

P265 75 R16 = 31.6 x 10.4

 

Actual Speed at 65 is 67.3

 

You can go to this site for other good calculators to figure this sort of stuff out easily http://www.tyres1.com/calculators.html

[76BBSub]

Difference is 20 mm across the tread, theoretically anyway.  If you look up the actual treadwidth specs from the tire manufacturers you will find some discrepancy between listed sizes and actual sizes.  BF Goodrich publishes actual treadwidths for some of their tires on their website, that may give you an good idea of the actual difference.

Jeff

[Shaners]

If you don't reprogram, then it will make it seem like your mpg's are less (unless you try to figure in the extra miles).  If you don't reprogram, then you will be able to put more miles on the truck than the odometer will show. (Like Chevy4x4 said, add on 3-4 mph to what your speedo reading is on the highway to stay within reasonable speeds  ie. "no tickets")

[chevy4x4trucks]

I switched to P265's from p245's and really I haven't noticed the speedo being off at all.  I don't think the trucks come programmed for either one, probably somewhere in between.   It's such a nominal change that it's not even worth it.  But if you're concerned get a HPP III as opposed to paying the dealer to do it.

[badpewterz]

your speedo will be off they are programmable on the trucks per which tire size you have and will also mess with your abs system

 

i had p245/75r16 gy(stock)

just got my bfgs on today lt265/75r16 and gained over an inch in flare height and they also look like a truck tire unlike the goodyears

 

i will be reprograming my truck tommorow too

[illmac77]

i switched from my stock 245's two 285's wrangler AT/S man what a difference it looked like the tires were ment for it, i also reprogramed it with a hppIII bout a month after, before then i was about 5 mph faster then with the 245

[dogdays]

My 93 Sub with stock 245s needed 83 mph to go a measured 80.  I calculated the difference, added a new set of 265s and the speedo is right on across the board, isn't more than 1mph off anywhere.  No revamping required for my setup!

R.

[Stepside Z]

I switched from P265 Firestones to LT285 BFGs and what a difference. I think my speedo is off by only a couple of mphs. I have a friend that is a cop that is going to clock it for me. I will get back to you when I get it done.