What gas mileage difference did you notice when you started going up in tire size

So recently I picked up a set of SCS SR8 because my OR wheels and 275\70\18s were just drinking gas. I was thinking knocking 4 lbs off a corner would make a bigger difference but I haven't noticed much. I was thinking about dumping off my Wildpeaks which weight 61 for a set of Toyo AT3 which weigh 52 but it's a hell of a dump of cash to try and maybe get a mile or 2 mpg.

So my question, does anyone have any objective numbers on when they went down or even up a size that they had as far as gas mileage?

 

Moved from the stock 18 inch tires with the OR package and installed rather light Cooper XLTs (about 55lbs?) size 275/70 (33s) in load range E on the stock wheels reduced MPG 1.5-2 MPG.

The larger diameter, more aggressive tread and heavier weight of the tires is going to reduce MPG by about 2mpg or more depending on the tire size. So what you are experiencing is typical.

If MPG is a concern stick with 32 inch tires with a highway tread pattern and stay with standard load rating tires which are considerable lighter than E load. Moving to 33s or larger (and most all of them are E load so heavier) is going to cost some MPG.....no way around it.

I would not replace the tires until they needed it. The cost of the new lighter tires will never be pay for themselves in MPG savings.

 

One more thing- LT tires require higher air pressure than standard load tires. So, adjust accordingly. If you are running pressure based on the door sticker you are underinflated and that will reduce MPG a good bit. If you have 275/70s LT tires, front pressure should be in the 40-45 lb range, rear about 40lbs or a little more depending on load.

There is a good sticky in the wheels and tires forum here about air pressure and how to calculate correct pressure when moving to an LT tire. Or you can always perform a chalk test.

 

Tires make a big difference. Went from OEM TRD OR wheels with stock Michelins getting 18mpg to 15.5mpg with 295/70/18 10 ply Falken Wildpeaks. Gotta pay to play!

 

Went from stock '2016 18" TRD wheels and "standard" AT tires in the 31-32" range to 17" Fuel Vectors and 35x12.50 Mazama Open Range AT tires a couple months ago. I was averaging 14.5mpg before. I'm now sitting at 13.5 mpg's.

 

I went from 14.5 to 13 going from stock Michelin to 275-70-18 Nitto RGs. 6112 and 5160s were installed at the same time.

 

Lts here run 35 in front 38 in rear no issues with wear or mpg always around 15.5 mpg hand calc

 

So much this. OP is just lying to himself to justify buying new tires and wheels lol

Want better gas mileage? Drive a beater car to work that gets 30+.

 

Man oh man...on trips, I push my "80 psi max" LT Coopers to 65 in front and 60 in rear when driving long distance without winter hurdles...I stay around 65 all around when towing too...right now, even in winter months, I'm holding at 50psi all around and it does great with 600lbs of sand in the back! I'm averaging nearly 13.6-14mpg with the current setup...

 

How are your tires wearing?

 

Wearing as they're supposed to...no cupping, drives straight as a pool cue, no weird hops/bumps/shakes...they are one size up (275/70/18) Cooper RTX...I've always have my LT tires on all my vehicles higher then a tire store suggests...much wife's 4runner is wearing 255/80/17 Cooper ST Maxx at 50 psi too...all rotations are done every 10k miles or 2 oil changes...

 

What are MPGs?

 

Some sort of math problem no doubt...I would rather pay for fuel then repairs, that's why I'm a Toyora guy...