With the 32s (up from 31s) I have lost about 3 MPGs or so. Previosuly I got between 300 and 315 per 16 gallon tank. Now I am getting about 250 miles per tank.
About 18-19 mpg previously - now I am averaging around 16MPG.


Definetly a pretty big MPG loss, but what can a Yotatecher do?

 

man...id be dammned if i can get 250+ out of mine!

I have a 3.4 4runner.

now im looking at 220 with 285s

oh well...gotta pay to play

before i was getting aroud 230..LOL

 

how aggressive was the tread on your 31s? and on the new 32s? Also - are you taking into consideration that your odo is probably off due to the larger diameter tires?

I found that I lost very little MPG going from 29" ATs to 32" ATs, but I lost a lot going from 32" ATs to 33" MTs.

 

huh - I didnt think about the odometer - what difference does it make? How can I compensate for the different diameter? If my odo reads 250, is it more or less distance that I have actually travelled with the bigger tires

also - I went from 31" Wrangler RSA(light highway tread) to 32" Dunlop Mud Rovers. So that is probably one of the big reasons I have seen a drop.

 

yes, your tread will make a difference. The odo will be off (read lower than actual), but since you went from 31s to 32s, the differences should be rather insignificant. There are calculators on-line (check out off-road.com) that will tell you what your odo/speedo are reading compared to the actual mileage/speed... but I don't have any of them bookmarked at the moment.

 

I went from AT31x10.50's to AT33x10.50's and didn't notice much of a drop.

I checked my speedo after against GPS - GPS says 71, speedo says 70. Not enough different to worry about. I wouldn't waste my time with the calculator, because that assumes the stock speedo was correct, and in my case it wasn't.

My guess it's more to do with the tread pattern/compound and weight of the tires, possibly the width too.

 

The odometer will be low by about 3%. Not really a huge difference, in your case probably around 8 miles per tank. Assuming you have a true 31 and 32 inch diameter tire:
31" x PI = 97.495 (Rolling Circumference)
32" x PI = 100.64

 

This speedo calc is spot on if your truck came with 31's as stockers. If not, you need to start w/ the stock tire size and then calculate the new tire size to find out approximately how off your speedo is.

 

I went up from 265/70s to 265/75s on 16 inch rims, which is close to your size. I notice a slight drop in the gas ileage, but I ride the same route to work every day for 5 days a week, and I notice the gas guage always went from full to 1/4 of a tank in those 5 days, and it still does, so I really don't think I suffered any noticeable loss. As for 280 miles out of a tank, Im doing 180-200 with the wind behind me. (NJ driving is nasty though)

 

Here's my gas mileage progression... All mixed hwy/city driving

Stock: 20-21 mpg
Lift & 32" Tires: 18 mpg
SCr: 17 mpg
SCr & Winter Gas: 15 mpg

 

yeah - the winter gas is a bummer.

 

Wow, I only wish I got that good!

 

you're telling me....thats about what i get with 265/75s

 

I have a 99 3.4 4x4 just stock with 265 75 16's Hwy Best so far is 300 on a tank driving 75-90 miles an hour,average is 285, Street no hwy 200 miles per tank. IF I broke it down it, I would cry so I won't.. Still worth every cent for gas! I have some over priced street "AT's" Looking forward to some BFG's KO AT's!!!!

 

Im running a stock 01' 4Runner, and get 20.x MPG regularly. I guess I drive with a light foot??? I do primarily drive highway, but even around the town driving, it still gets around the 20.x MPG.

 

your speedometer and odometer are actually reading lower, so your calculations are off.

i got my truck calibrated, and check with my gps. at 70 (speedo) gps says 75 or so.
went from 31->32"