Gas Mileage and tire size

I currently have 265/75/R16 GeoLander X-AT on my Tacoma Sr5 Special Trail Edition . It has a factory 1.1 front coil spring lift on the front and a .5 lift on the rear .At the time I put my tires on the only 255/85/R16 that was availble was a mud terrain .Falken now has a 255/85/R16 AT/4 available .So this a multiple part question as far as looking for advice . If I switch to the Falken tire do i have to worrry about rubbing and a loss of gas mileage ? I do not do off roading mostly highway driving but do a ton off hunting where i do go off the beaten path .I definetly do not want mud tires and wish Falken didnt come out with this tire in a AT I would never been even thinking of this . I would love the greater ground clearance and the look of the fuller tire in the wheel well but do not want to loose gas mileage and rather get better gas mileage .Any help advice on this would be greatly appreciated .
Thanks

 

I have the factory lift on my 2021 offroad and run 285/70/17 BFG KO2s with zero clearance issues at all. There's a definite reduction in mileage over the factory 16" tires tho. Also my speedometer reads 3 mph slower.

 

Welcome to the forum

Here is a comparison of the two sizes:

 

The rolling resistance of a tire is dependent on more factors than just size. Tire compound, construction, tread pattern, air pressure, etc. also affect it.

For example, an all-terrain tire will generally have more rolling resistance than an all-season tire and a LT tire will generally have more rolling resistance than a P tire.

 

Wide tires hurt fuel mileage more than narrow tires. The more aggressive the tread, the bigger loss in fuel mileage. I've seen mpg go from 19 to 16 mpg going from an AT to a mud tire in the same size and load range. Taller and heavier tires, (within reasonable limits) have much less of an effect.

Taller tires effectively change your axle ratio giving you a little less power and making the engine work a little harder to get moving or when towing. They also cause your odometer and speedometer to be inaccurate. Your onboard mpg calculations will look a little worse than they really are. But if you account for the differences in your odometer and hand calculate fuel mileage there isn't that much difference. Your odometer may say you've driven 200 miles, but you may have actually driven 215.

Heavier tires are harder to get moving, but once up to speed don't take any more fuel to keep them moving. If everything else remains the same heavier tires may reduce acceleration, but have very little effect on fuel mileage.

If you only change one thing neither performance or fuel mileage is affected much. But most people change multiple things all at once. If you go to a taller, wider, heavier mud tire all of that combined will make a significant difference. Going to a 255 series tire vs a 265 series will help offset the slightly taller tire. But the mud tread and weight will reduce your fuel mileage and performance some.

A lot depends on how much power you have to begin with. Guys driving a diesel F250 have power to spare. Those guys can go to a 12" wide 35" mud tire and see virtually no loss in performance or fuel mileage. Put that tire on a Tacoma and the difference is significant.

 

Thank you all for your help . Leaning more towards just keeping with what I have . Less chance of a divorce as well .

 

Is the bigger tire with the strain on the engine a concern for engine wear or is that where the gas mileage gets lost

 

Energy is lost through the rolling resistance (aka friction) of the tire. Tires flex when they roll and that causes them to heat up. That heat is lost energy that reduces your fuel economy. There are also some aerodynamic losses, but I can't speak to how significant they are.

https://en.wikipedia.org/wiki/Rolling_resistance

 

Bingo.

As far as rubbing it's hit and miss with each Taco. Mine don't rub, and I kept my mudflaps.

With the 2" lift and 33" pizza cutters, I have crazy amount of ground clearance.

 

That’s a nice looking Taco

 

The weight and tread design of the tire has a big effect on mileage as well. I run stock size Goodyear Ultra Terrain tires in the winter. I lose about 2-3mpg on the highway.
They are heavy and aggressive compared to my Michelins.

 

I went with a smaller 255 tire.

You may or may not rub. That size is right on the edge- some people do, some dont. It depends on how much sharp cornering or bumps you experience. You will however hurt mileage despite it being a skinnier tire. Those Falkens are 58 pounds per corner, and that's a lot of weight.

If that truck is a daily commuter, I would consider keeping it to 32s.

32s are cool.

 

Looks sharp with the gunmetal wheels.

 

Sweet ride thanks will take your advice . It’s is a daily commuter and also my road trip vehicle. Heading out to Colorado in two weeks from Chicago

 

I used to run WildPeak H/T 265/70r16 on stock suspension and also when I threw on bilstein 5100s they gave me on average 18-22 mpg on highway driving (100-200 mile drives). When I had Falken Rubitrek A/T in the same size I averaged 17-20mpg across the same distance. I run 285/70r17 now with wildpeak at4W and average 14-17 mpg on highway but honestly feels like I am still visiting the gas station around the same amount as I did with smaller tires.

 

I absolutely love my 33"x10" widlpeaks, mind you they are 255/80/17. At 52 pounds each, I have noticed no measureble difference in power or MPGs coming from C rated 265/70/17 KO2s.

Im planning to buy exact same tire brand/model and size for my next set.

Hope that helps.

 

Right on.

Great compromise tire and size.

 

Same here.

2' lift. Sema wheels, 33"x10", stock mudflaps - zero rubbing.

 

If you go with pizza cutters (255 or skinnier), I wouldn't worry about it at all.