How much, if any, should I expect my fuel economy to drop when I change out my stock 245's for 265's? I just don't want any surprises? Does this throw the DIC off if you recalibrate for the larger tires? Thanks
After almost 6 years on 265's, MPG change was minimal if any. That was with one LB7 and 2 LBZ's. All my trucks averaged around 18 or so pretty conistantly, always hand calculated, when going from the stockers to the 265's.
If you are using a programmer to recalibrate for the 265's, your DIC will probably be off anyhow, though your speedo will be correct. Even with the stock 245's with a programmer, the MPG on the DIC will probably be off.
I doubt you'll see much difference. Calc it by hand before you change tires for awhile, then after the 265's, also calc by hand using the correct adjustment for tire size ( miles X 1.039 I think ).
I get about 16 in town and best hwy was 22, with the 265's. I changed my oem 245's out at 500 miles, but I was getting 16 in town, too.
IMHO, the 265's are the perfect size for this truck, with an A/T tread.
I doubt you'll see much difference. Calc it by hand before you change tires for awhile, then after the 265's, also calc by hand using the correct adjustment for tire size ( miles X 1.039 I think ).
I get about 16 in town and best hwy was 22, with the 265's. I changed my oem 245's out at 500 miles, but I was getting 16 in town, too.
IMHO, the 265's are the perfect size for this truck, with an A/T tread.
X2, right on the money as mine did. I changed the tire size at 24k when the tires wore out and put on 265's. I have been getting 14-16mpg around town with warm-ups and stop light traffic. My best was also 22mpg on a trip. All done by hand calculation. The formula above is also correct too.
x3 I never noticed any real difference on mine either. Like they said above, make sure you hand calc and compensate for the difference in tire size. I usually get around 17-18 highway and 14-16 in town, before and after the tire swap.
my truck was getting 17+ mpg i put a set of 265 75 16 mastercraft ct's and im only geting 15 mpg. I had the speedo reset by my friend that works for the local gm dealer with a tech 2 scan tool. I guess maybe i need to get a programer on it. my fuel filter also has 5k so i could have got some crappy fuel
After wind resistance i believe rolling resistance is the next big factor, i.e. tire size and tread design. someone that tows heavy all the time would probably notice a drop in mpg going from 245's to 265's. Just driving around empty probably not much at all.
i towed alot and lost about .5-1 mpg loaded but gained 2-2.5 on the highway empty. I also had 235/85s so they are the same hight but not as wide. If i stayed under 70 i was getting 23+ hand calculated( i know no ones gonna belive this but i monitor it on a spreadsheet for my buisness)
I put my 265's on after only a few hundred miles so I really don't have a good idea of mileage on the 245's. My speedometer is checked with radar is now very close (+/- 1 MPH). Mileage varies, depending on how I drive.
Freeway:
55 MPH (who drives that slow?) 22 MPG
65 MPH 18 to 19 MPG
75 MPH 16 to 17 MPG
In a nutshell, your driving habits will yield the best return on mileage and tire wear. I know, I wore out the first set of Toyo 265 AT's after only 25,000 miles. No burn outs, racing or power braking, just aggressive acceleration and hard stops. This truck sure is a lot of fun.
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