Tire size question

Currently running 31" highway terrains on my truck and from stock it didnt really mess with my mpg. If i go up to a 32" trail grappler and leveling kit will it screw with my truck a considerable amount or no? Im talking mpg, handling etc. thanks.

 

The important thing to look at is tire weight. If you are stock you are P-load. P-load is best for street use and ride. If you want something more durable for offload, look at C-load, which are a little heavier. Avoid ultra heavy E-load as both ride, handling and mpgs will be negatively affected.

Tirerack.com is a great site for checking tire specs.

 

I have P265/75/16's on mine with no lift. This tire, http://us.coopertire.com/Tires/Sport-Utility/Discoverer-A-T3.aspx They are a 31.5" tire and about 1" taller than factory options. Depending on who you talk to you'd round up or down and call mine 31's or 32's. I wouldn't want to go any larger without a lift. I've never had any tire contact any part of the fenders or suspension, but there isn't a lot of room to spare.

As far as power and performance is concerned you shouldn't have any issues with the size. My truck has 3.73 gearing and any changes to performance or fuel mileage were too small for me to notice. I stayed with a "P" series tire which is a lot lighter. Going to a heavy "LT" tire with an "E" rating would make a difference. If your truck is geared higher than 3.73 you might notice some loss of power.