245/75 to 265/75......Difference in Fuel Mileage?

Just got a new 2013 Tacoma PreRunner V6 Auto and it came with the 245/75-16 tires on it,for anyone that has made this change, how much fuel mileage loss could i expect going up to a 265/75-16? Thanks in advance.

 

If you do not get your speedo re-calibrated, you will actually be driving more miles than your odometer shows. Example, If you drive 300 miles per the odometer, you will be driving 324 actual miles. That will show a decrease in MPG even though you may be the same or slightly lover (1mpg or less probably)

The revolutions per miles on a 245 is 682 revs per miles. The 265 is 657. The circumference of the 265 is about 3 1/2 inch larger than the 245.

You can compare them at the below website.

 

Thanks I am aware of how to calculate the difference in speed read and the affect on the ODO, was just looking for real world performance difference. A loss of 1 mpg isnt bad, just wasnt sure how sensitive these Tacomas are by going up an inch or so in size. My last Tacoma was a 1999 with a 3.4 and a standard tranny.

 

i seriously doubt you'd notice anything fuelwise at all.

 

I went from gettin 22-24 on an 18 mile one way trip to 18.5-20.5 4 mile trip to work when I changed (changed jobs) I actually got 21.5 with a 420 rancher in the back goim to the hunting club and back about 160 miles round trip counting driving on the club so not enough difference ti not get it in my opinion. Speedo actually read about right now acording to how mileage how ever is off about 4% Toyota doesn't have the speedo set right my wifes rav4 is off about 6% and odo is on.

 

Thanks for the info. I am not looking to get big tires its just that the 245/75's look so skinny on this truck. Thinking that the 265/75's would make it look a little more filled out in the wheel wells. I traded in a 5.7L Tundra and the last thing I want to do is sacrifice the better fuel mileage this little truck affords me.

 

Tires will look better. Probably 1-2mpg difference.

Didn't mean to insult your intel, some guys don't know there is a difference and see 4-5 mpg difference and thinks its all about the new tires causing the issue.

 

No insult taken Scott, I knew where you were coming from. You are correct in that many guys dont know that all their readings are off when they go up 1-2 sizes in tires.

 

What's the deal with the speedo being off in the stock configuration ? Is this common?

 

My conspiracy theory is that all manufacturers are taking the speedo error to the limit in order to boost their CAFE scores. If a speedo is 3.5% out like my 012 Tacoma is, my mpg is also boosted by 3.5%. For example, when I achieve 20/mpg it is really only 19.3!

 

the speedo is off but the odo is still on. we took my wifes car to disney world, a trip my father-in-law (who happends to be a truck driver) has made 20 times or so, and he said it was 660 miles from his house. when we pulled up to the hotel the trip odo read 659.6, if it was 6% off like the speedo was it would have read 699. u can look at some of super wertys videos from inside when he does his 1/4 miles and see that his speedo says 110-112 and his speed at the track is 106.

 

Actually with my 245's the speedo was 2 mph slow. Going to 265's the speedo is correct now, but the odometer is 3.7% off. 10,000 actual miles is showing 9600 miles on the odometer.

 

So then going with the 265's seems like a good choice on multiple fronts. I just really didn't want to have tire buyers remorse if it affects my mileage significantly. What I don't understand is how Toyota gears these things for so many different tire sizes that are offered in the different models with a 4.0 and an auto trans, everything from 245/75/16 to 265/70/17 and running the same gear ratio which I believe is 3.73.

 

I don't know, i could be way off base here - I mean you guys know alot more about tires than I do.

But I'm thinking theres going to be at least a 2-3 mpg loss with the 265's. Of course depending on the tire. But the 265 is going to weigh alot more than those 245 dunflops, and it's almost an inch wider which is going to add road resistance.

 

I just made the swap last month after doing 5100's all around. I lost maybe 1mpg adjusted from the stock tires. If you stay with a P metric 4 ply tire the weight difference between 245's and 265's is about 5 pounds on average.

 

OK...
Have 2 trucks, have checked them by GPS and other ways, the speed is off a % on both, best I can say is that a 74 MPH on the dash the trucks are moving 70 mph...

Called Toyota, wanted it fixed and they said they can not change it, tech said it is set to the largest tires on the truck and should read correct with the 265 size tires and I have 245.
I ask if that is legal as it is putting more miles on the truck and they said it is set at the max of the limit the Gov lets them.
THey told me they could no program in the tires and chang it.

On the Dodge they program in the tire size to correct the speed and miles. On chevy they changed the drive gear, little plastic gear for the spedo, and the newer ones they program.

I call BS on Toyota as it is running more miles then it is and more MPH then you are moving.

Both tested.
Toyota said something about a Class Action that was on the milage as they had it set high in the past to run you out of warrenty faster and that was the reason it could not be programed....

Don't know what to think about all that, other then I do not like the fact two trucks, factory shape, both off the same speed and adding more miles then it should.

BTW it was tested with a test wheel held on the outside of the truck, it is off.

SO when I add 265 tires that should put it back to the normal speed and miles on the trip.

 

I made the transition from 245/75-16's to 265/75-16's and have noticed approx. a 1 -1.5 mpg difference in my mixed driving fuel mileage. Kind of bummed me out a little bit but when you factor in that the speedo and odo are off with the 245's it came with, its really a mental loss, not actual.

 

Gonna do this soon too, the 245 dunlops are about done and look wimpy anyway.

This has me wondering...will a 265 fit in the stock spare location? or do you
guys stay with the 245 for the spare?

Thanks.
PC

 

I noticed when I went to the 265's I seemed to have lost at least a 1mpg. I did lift the truck with 5100's to 1.75", so maybe the combo of the larger tire and less areodynamics helped in the loss. I am running a 5 ply P rated tire as well.

 

I'm confused... The TRD offroad has 265/70R16 and it reflects the same MPG as my SR5 with 245/75R16 on the sticker??

I just want a wider tire that does not look like pizza cutters.