Tire Load Ratings & MPG's

Will the same size tire in a higher load rating decrease MPG?
Considering it is the same brand, same size.

Or will the size of the tire have more effect on the mpg?

 

Higher load ratings entail more plies, increasing weight.

Depends on the difference.

 

The weight of the tire is the most important factor. Each additional pound of rotating mass on your wheels and tires is roughly equivalent to ten pounds of weight in the truck. So, if your E rated tires weigh a total of 40lbs more than the stock ones, its like having two 200lb passengers.

 

I have two tires; one is a stock size load E, the other is a huge P tire weighing the same as the load E.
Which gets worse mileage?

 

Well, if they weigh the same, the larger one would have more rolling resistance and therefore get worse mileage (assuming it was wider and not just taller). If it were only a bit taller, it would reduce the engine RPMs at a given speed, which would theoretically increase MPG. The problem there is that the truck would sit higher off the ground and would therefore be less aerodynamic. So, either way the bigger one would be worse.

 

So in this case, weight is not the more important factor.
That's why I said "depends on the difference".
Additional rotational mass is something to consider, but more depends on 'where' that rotational mass is added in relation to the axis than the actual weight.

 

Yep. I think the answer to the OP's question is a resounding "yes".

 

Yeah thanks
I have Load E KO'2 and I'm looking for a Load C tire and I'm wondering if I will get better MPG

 

All other things remaining the same, yes.
You must have took quite a hit on MPG.
I only lost 2-3 mpg when I put on BFG KO2 LT 265/75/16/E.

 

Using a 265/70/17 KO2 as an example, the C rated tire weighs 45.7 lbs and the E weighs 53.4 lbs. You would probably notice a small increase in MPG. Using the rotational mass formula, it would be equal to removing 308 lbs of weight from the truck (learned this shit from an engineer, not making it up). http://www.bfgoodrichtires.com/tire...es/all-terrain-t-a-ko2/tire-details#techspecs

 

Yeah that makes sense, thanks guys.
I feel like the 285/70R17 load E really bogs down the Tacoma.

 

I'd like to go with the 265's but I have about a 2.5 - 3 inch lift and I'm not sure if it will looks funny.

Anyone have a set up like this? Pics?

 

I'm running Bilsteins on all 4 corners and the front is set at .85. I'm running 265/70/17 Hankook Dynapro ATm tires. You can judge for yourself because your truck is sitting higher. Since your truck is higher then mine I'm guessing that the 265/70/17 tire may look kind of funny.