Best tire size?

Hey I just purchased a 1998 Tacoma sr5 4x4 3.4L 5 speed extended cab and it has 265/70r17 tires on it as of now. I would like to get the best mpg possible and believe having stock tire size would help. This truck is mainly a work truck and does not see any off-roading. I check the driver side door jam for the sticker with all of the specifications but it is not there. Would 225/70r15 tires speed the engine up too much at normal driving speeds? Or would 31x10.50r15 tires be the better choice? Any advice is helpful. Thanks

 

Well, It sounds like you currently have a 17" rim based on your current tire size, so without changing wheels, the two R15 tire sizes you mentioned won't work without new wheels. If you go back to a stock 15" rim, the 225 tire will get better MPGs because it weighs less and has less rotating mass. It will look pretty goofy, and the difference in MPGs will be pretty negligible. So, in summary, figure out of you are switching rims, then pick a tire with the least aggressive tread and weighs the least if MPGs is the goal.