[evangelos k]

I have an 03' Tundra, w/ 265/70/16 "upgrade from factory" tires.

My question is... Is the speedo calibrated according to the "from factory bigger tire" upgrade? I mean the base size is 245/70/16, and the 265/70/16 is a 3.6% off difference to the speedometer.

I find it difficult to believe it is calibrated, but on the other hand, it is also difficult to believe that a manufacturer would have a bigger tire upgrade w/o correcting a 3.6% difference on the spedometer.

 

[evangelos k]

Anyone knows the answer to the above?

 

[dcab03]

Your best bet is to have somone pace you in another car and call out the speed to you to check it.

 

[rambrush]

I use my GPS and it works great for that sorta thing.

 

[Chad30]

Just go 60 MPH between mile markers on interstate, should be exactly 1 mile. If not you have an idea how much your speedo is off!

 

[jaegermeister]

I have the 245's on my '04 tundra and the odometer reads slightly more miles than actually travelled - so I would say the truck is calibrated for the 265's. I've measured it against mile markers on the interstate and 3.6% as mentioned above sounds about right - I'll bet with 265's my odometer (and of course speedo as well) would be spot on.
Unfortunaltely, this means I'm actually getting worse gas mileage than I think, but hey - if mpg was that important I'da stuck with a tacoma!!!!:clown:

 

[Gatorman76]

I have the 245 70's, also. I read 57mph on my gps when the speedo reads 60. You're getting about a mile per gallon less than you figure. I think it's calibrated for the 265 70's. A 245 75 would work, too. But the bigger tire may hurt your mileage more.
Even so, I'm going with a 245 75 AT when these stocks wear out.

 

[cupidstoy]

try using the search feature. this has been discussed time and time again and there are tons of calculators and advice on this forum and online...

;-)