I have a 4x2 v-6 4runner. I have heavy duty shocks on the truck. I am also running 31in BFG T/A KO TIRES. I am seeing 17 mpg and about 280 miles per tank.
I've been getting a good solid 20, sometimes 21 this summer from my T100. Only done a couple of highway trips, estimate it at 24-25 on those. Most highway trips were pulling a 1977 Starcraft popup camper, with a few pounds added to it. Also did one trip with said camper and 3-Wheeler in the bed. Still geting about 18 or so when pulling. Hard to tell though, usually didn't refill when I got home and finished the tank off, so that skews it.
I'm very happy with this mileage compared to DDing my FJ-60. Getting 400 miles per tank very regularly.
I will add, I have a bed cover, maybe it helps maybe not. Have not driven it enough open and closed to get a good feel. Only had the truck since May, but I do think the cover helps. Plus I like being able to toss stuff in there and it can't blow out. Yet it rolls up in seconds to open the entire bed up.
