How much does tire weight really affect performance/mpg?

For what its worth, when i swapped out my stock all season 245/16 firestones for my spare set of goodyear 265/16 a/t adventure tires early last summer i notice an immediate drop in fuel economy about .5 mpg on average.

 

I just went from stock 265/70/16 Wrangler Kevlar’ as
That had 4/32nds left on the tread to the Falken Wildpeak At3ws. It went from 37 lbs to 43 lbs per tire and my truck feels like I’m driving through sand. It’s slow to initiate turns, takes longer to stop, and my foot is getting a work out keeping the pedal down more. There has to be something to the weight issue. I get that 37lbs is light, but I think I’m going to return these for the Toyo Open Country ATIIIs to save two pounds and hopefully get some better performance.

 

Depends a lot on your typical drive cycle.

With lots of stop and go that's lots of spinning the tire up then using brakes to spin it back down, it will be a bigger hit to mileage.

Lots of highway you may not note a significant change

 

How much air are u running in those tires? I went from the stock size to s set of 265 75 16 falken wildpeaks and honestly didnt notice a performance difference . I did lose 1 mpg over stock tires. I have 35 psi in the tires.

 

I'm about to pull the plug on buying Fuel Vector 17x8.5's with K02 275/70's. I'm really concerned about the weight increase moving from Bridgestone Dueler H/T (36 lb) on stock '09 TRD Sport wheels to Vectors on to K02 A/T (55 LB). I feel like my MPG sucks right now. Am I overthinking??

 

Daily driving with stock gears/67lb 35s and like 30lb wheels, I get around 15-17mpg (after calculating for the tire size difference) and can pull up to 21 mpgs on the highway on a long trip.

 

You're adding about 25lbs to each wheel with that setup. I'm not sure how much your mpg will go down but your acceleration definitely will be less.

 

I'm now headed toward to 265/70 C-Load. I don't off-road or tow much. Those are about 10lbs less than the 275/70. My main concern is ride and mpg. I also was wondering if there's really that much of a visual difference between the 265/70 and the 275/70?? I have 265/65 Bridgestone Dueler HTs that the previous owner put on the stock TRD Sports.

 

I changed from stock tires to Cooper STMaxx 265/75/16, 32” tall and 55 lbs, I saw no real change in MPG.

 

I know it's been said in this thread before but just figured I would reiterate - weight isn't the only thing to consider when upgrading tire size, but size itself is also a factor. If you have the same weight tire in a larger diameter, your truck will have to work harder to rotate the larger tire. Think of the opposite effect as a breaker bar - your truck has to turn the "breaker bar" (tire) from the inside (the hub). The longer the bar (taller the tire), the more difficult it is to turn.

 

Another thing to consider is that the ultimate factor deciding your mileage is how you use your right foot. You control the engine throttle, how much fuel it gets and ultimately how much power it is making.

If you go up a size to a heavier tire but keep everything else the same and maintain the same rates of acceleration it’ll require more fuel and hurt mpg.
On the other hand if your driving habits change and you drive more leisurely, you can get decent mileage. It’s all just physics.


I knew a guy with a 2500 Chevy with a 454 on 42’s that could squeeze 13-14 mpg out of. The key was driving like grandma on Sunday.

 

The losses for tire size come down to what you do with the brake pedal. It takes more energy to spin up a larger tire, but now it's sort of stored in a larger flywheel, and takes about the same amount of energy* to keep you rolling down the road.

Now to get slowed down if you take your foot out of it sooner and let it slow down on it's own (maybe in gear to use that sweet deceleration fuel cutoff) and all that fuel used spin up the tires gets extracted as distance traveled...if you keep cruising it until you have to brake, that extra fuel you used to spin up the tire gets dissipated as brake dust and heat.

*Sameish different tires have different rolling resistance and drag.

 

A little more weight on the truck now and have beadlocks, still getting 14-15 daily driving and got it up to 18mpg on a full tank of highway driving last week.