Is anybody here running, or thought of possibly running a taller, skinnier tire, lets say a 245/70R17 or 245/75R16? (Something along those sizes) I know it would look kind of goofy being a narrower tire, but it might get you better gas mileage if your 4th gen is mostly a highway cruizer. Thoughts?

 

Smaller tires = more mpg, yes with narrower tires you get less rolling resistance but you trade off due to height as they weigh more.

If you want the absolute best mpg out of your truck buy highway tires and get the smallest size that doesnt look goofy. That will give you the best mpg along with driving easy and keeping the car in tune.

 

I run 235/85/16's. they are 32"x 9.50 and are load range E. heavy? yes. Impossible to puncture on stobs because the toyota isn't heavy enough? yes. 65K miles on a set of generic mud grips is another nice bonus. With my 1991 V6 5 spd I was getting 20-21mpg.

 

i got 18.5 in my taco w/255/85/16 bfg's this weekend

 

hmm ... i'm runnin stock 265/70/16 & getting ~17.5-19mpg

 

there are lots of factors that go into it if you really drill down to it

skinnier tires have less rolling resistance = higher mpg

skinnier tires have less material than fatter tires = lighter weight = higher mpg

taller tires have more material than shorter tires = more material = lower mpg

taller tires have a larger radius, larger circumference, and thus travel farther than what your odo and speedo say = higher mpg

all those alone have effects but i'd say the weight is the big thing so in general, the best mpg you can get is with lightweight tires which usually means skinnier and small diameter.

tall + skinny versus short + fat, i'd say tall + skinny gets better mileage but its all negligible