do you NEED to adjust gear ratio after tire upgrade?

I have been running 265/70/17 Firestone Destination ATs for 1.5 weeks (400miles) on my '07 V6 sport.

I've noticed a drop of 2.5mpg, and experience the same problems mentioned above.

I really don't mind the lost in gas mileage as much I hate having to work the throttle more when going uphill. It's even worse when the vehicle in front slows down. If I have to ease off the throttle at around 45-50mph, rpm drops from 1600 to about 1100/1200. This is really frustrating Also, coming from a turn, I don't seem to have that exit speed anymore

The good news is that Tires Plus will swap out my tires tomorrow with original spec since they have a 30-day warranty period. I just have to pay for the $50- total price difference

Do you guys think I need to get another alignment done? I just had the dealership do that last week for $99-

 

When calculating the % change in tire size use the circumference, not the diameter.

I re-geared to 4.56 and love it. Definitely needed with the 4-cyl if you get tires any larger than stock.

 

With all the good info I've got from this forum, I've decided to go with 285/70 x 17's on my 2006 TRD Offroad DC. Besides helping with the strain on the larger tires, would a set of 4.11 gears bring the speedo / odo back to true?

 

Yes

 

You are mistaken sir. The ABS Sensors have nothing to do with the speedometer. If you don't believe me, go unplug yours and find out for yourself.

 

Lol, I guess we have an answer. That really sucks for Auto transmission guys.