I lost 1-2 mpg when I went to all terrain t/a. I have a zr2 and if im right, they were originally more of a highway tread , rugged terrain maybe? They weight more so the rotating mass might be hurting also

 

So, I know it's kinda an old thread, but with the 6" lift and 33" tires, my mileage has gone to crap. 11mpg calculated, but the speedo is way off. Probably around 13, maybe 14 mpg

 

Stock tires were Long Trails. Great on road but terrible off road.