Tire Size adjusting

[volvite]

All,

I had some bigger tires installed on my 08 Pathfinder. I'm wondering I can adjust the settings on the computer to the new tire size with an OBD II scanner or if a trip to the dealer is required.

[05Pathfinder]

Im pretty sure you cant change it. Instead you should have just got a tire with the same overall size. To check the difference go to http://www.miata.net/garage/tirecalcold.html

[gond34]

Volvite,

Same issue when I switched to the DuraTracs... Seems to be about a 2 mph difference in actual speed vs. speedo reading and it also seems to show about 2 mpg less on the computer now as well...

[NVSteve]

Each model year, all of them are fixed/calibrated to one specific tire size. With the 2007 model year, for example, each model is calibrated to a 265/75/16 size. If someone with a 2007 is running a size bigger or smaller than that, everything will be off. Since most are running a size or two smaller, a lot of people out there think they are getting better gas mileage than they really are. I've asked two different dealerships about reprogramming the CPU for other tire sizes and have been told it can't be done. No idea if this holds true for all model years or not.

[disallow]

I'd check your speed vs GPS or Radar. I found that with my bigger tires, the speedo was actually reading correctly, and that with normal tires it was 2-3% under.

[volvite]

Each model year, all of them are fixed/calibrated to one specific tire size. With the 2007 model year, for example, each model is calibrated to a 265/75/16 size. If someone with a 2007 is running a size bigger or smaller than that, everything will be off. Since most are running a size or two smaller, a lot of people out there think they are getting better gas mileage than they really are. I've asked two different dealerships about reprogramming the CPU for other tire sizes and have been told it can't be done. No idea if this holds true for all model years or not.

Thanks. The reason I asked, with my 99 Jeep the dealership could only adjust a little either way. However if I had a 03 version, same motor, same body style, it's all digital and they could adjust it to any size tire. I thought the 08 Pathfinder would be digital and allow adjustments.

[axlesup]

the triple gt tuner i have wont change it for nissan. its funny cuz in my year they came with three different tire sizes. all different heights.

at 128MPH (GPS verified) im only showing 122MPH with my 275-70-16 tires. that is about the point it shifts out of third into fourth gear. also the point that i ran out of road er i mean race track and had to hit the brakes.

i have to give the pathfinder credit for running on a rough road i mean race track at that speed with one finger on the steering wheel!!!!!!!!!