heavier trailer tires and fuel economy

Fuel economy? Complex subject!

Long Version: Barry's Tire Tech: Rolling Resistance and Fuel Economy

Short Version: Rolling resistance in tires can vary widely - up to 60% within the same size.

More pressure = less rolling resistance - all other things being equal, but we are talking about a few percentage points, where differences between tires can be double digit percent.

LT tires get worse fuel economy than equivalent P type tires because LT tires are made of a less compliant rubber (more internal friction = hysteresis)

I run 17.5 MT tires rated for 6005 pounds per tire and wheel combination on my fifth wheel, wheels weigh 60 pounds each, with tires weighing 65+ pounds. I run them at max psi of 125. Actually get better mileage than the 16" tires they replaced.

johndeerefarmer wrote:
I know heavier tires on your truck decrease fuel economy but what about on a trailer? Looks like once you get it up to highway speed it wouldn't matter?

why I asked was I got tired of the blowouts on the 12 ply junk and put some heavy 14 ply on my trailer. Wondering if and how much mpg will be affected

Thanks
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2020 Ford 350 6.7 PSD & 2017 F150 3.5 EB max tow
GD Reflection 29rs

If you are referring to the 5th wheel in your signature, get a good set of LT tires, and skip crappy ST tires. I run Yokohama LT 235/85-16E tire on our 12,360# GVWR 5th wheel. Your 5th wheel has a GVWR of 10,000#, the LT are more than enough tire for it.

joshuajim wrote:
It’s pretty well known fact that trucks that switch from lighter P tires to heavier LT tires always lose on mileage. Is it the heavier tire,the stiffness of the tire or tread pattern. Who knows.

Rotating mass robbs horsepower.

It’s pretty well known fact that trucks that switch from lighter P tires to heavier LT tires always lose on mileage. Is it the heavier tire,the stiffness of the tire or tread pattern. Who knows.

johndeerefarmer wrote:
I know heavier tires on your truck decrease fuel economy but what about on a trailer? Looks like once you get it up to highway speed it wouldn't matter?

why I asked was I got tired of the blowouts on the 12 ply junk and put some heavy 14 ply on my trailer. Wondering if and how much mpg will be affected

Thanks

Assuming the new tires run at higher pressure... I believe the fuel economy is more likely to increase.

Best if the tire load rating covers the entire trailer GVWR.

You paid for more tires it shouldn't bother you to pay a little more for the safety they provide.

it will effect it a tiny bit, the physical size has more effect than a small shift in weight. you could also see if there is one that is "energy conserving" or have a lower rooling resistance. this and how tight you pack wheel berrings and set your brakes have a larger effect than just a little bit more weight.

Yes, there will be some effect. Like Typer0215 stated, it is likely small enough not to worry about. Perhaps the heavier weight and stiffer sidewall will provide less flex in the tire, making it have less rolling resistance anyways. The comfort of knowing you have plenty of available weight carrying capacity makes me happy, even at the potential cost of slightly less fuel economy.

Not enough to measure.