I have a 97 Tacoma 4x4 V6, I currently have the stock 31" Goodyear RTS tires on and was wondering if I went to a 30" tire, if this would improve my gas mileage. I know my RPM would run a little higher, and feel a little more power due to the smaller diameter wheel. The Goodyears new, are 30.4" tall and I was thinking of going with the Bridgestone Revo's in a 30" tire. The 31" tires are 30.5" tall and the 30" tires are 29.6" tall. This is mostly driven on the street so I don't mind the smaller tire. It's pretty flat in the Sacramento valley where I live unless I drive into the mountains. Has anyone tried this? Do you think my mileage would improve or go down?