Which tire configuration use more fuel?

[karl lee]

Hi Bro,

I'm interested in knowing which tire configuration use more gas? Both are on 15 inch Wheels the only different is side wall.

1. 185/60R15
2. 185/55R15


Thanks.

[upgradedyaris]

Well, a smaller wheel and skinnier tire will give you better gas mileage. I had RS wheels on my car and sold them. They were 15" vs my 14" stock steelies. I weighed them and were 9 pounds EACH wheel heavier than the steelies.

HTH
Duane

[Tamago]

a tire closest to stock height will give you the most accurate mileage reading.

smaller tire will probably calculate to be 'better' mileage, but you're not going as far as your odometer says..

[Loren]

In theory, the tire with the larger diameter should give slightly better gas mileage. But, as Tamago points out, you need to be sure to correct your MPG calculations because the change in tire diameter is going to make the odometer inaccurate.

[karl lee]

My question is only base on the height of tire sidewall. Let's assume the odometer meter is correct.

I heard somewhere that shorter sidewall(lower profile) will have a better rolling resistance compare to taller. And also tire is slightly lighter. Therefore, should be better mileage for shorter sidewall tire.

Please share your view.

Thanks.

[Loren]

You can't maintain the accuracy of the odometer while changing the sidewall height unless you also change the wheel size, of course. But, making that assumption...

I'm not sure you'd get less rolling resistance with less sidewall necessarily. The factor there in either case is going to be how much the sidewall flexes, how round the tire stays. Radial tires are designed to flex a little bit, and it's that constant flexing and unflexing as the tire rotates that turns into heat and added rolling resistance. Stiffer sidewall (which can be acheived in ways other than just shortening the sidewall) flexes less, hence less rolling resistance.

A lower profile tire also isn't necessarily lighter than a taller profile tire. In fact, it's normally the opposite. A low profile tire requires a very stiff carcass, which requires more steel. Look up your favorite tire. Check different sizes of the same model of tire. The larger wheel/lower profile sizes are usually a pound or two heavier. Even if they were a pound or two lighter, it wouldn't be enough to make up for the weight increase of the larger diameter wheel.

[Tamago]

and as a rule, skinny tires = less rolling resistance. go buy tires for a prius lol

[why?]

I think that with most tire manufacturers finally actually listing tire weight, go check that out, it will make more of a difference then sidewall anyways.

Lighter is always better when it comes to gas mileage.

[scape]

Originally Posted by Loren

In theory, the tire with the larger diameter should give slightly better gas mileage. But, as Tamago points out, you need to be sure to correct your MPG calculations because the change in tire diameter is going to make the odometer inaccurate.

if it's mostly in town driving, i'd think a larger diameter might make matters worse.

[Tamago]

Originally Posted by why?

I think that with most tire manufacturers finally actually listing tire weight, go check that out, it will make more of a difference then sidewall anyways.

Lighter is always better when it comes to gas mileage.

so you think a lighter tire that's wider would save gas over a slightly heavier/skinnier tire?

are we skipping the physics class where we talk about rolling resistance ?

[why?]

Originally Posted by Tamago

so you think a lighter tire that's wider would save gas over a slightly heavier/skinnier tire?

are we skipping the physics class where we talk about rolling resistance ?

You know you couldn't compare just those two things, as you mentioned...

[karl lee]

Hi all,

My question is asking on sidewall only. Let's assume everythings is the same. Take this eg: 185/60R15 and 185/55R15.

I had found this website, you may want to check it out.

http://www.associatedcontent.com/art...n_vehicle.html


Thanks all sharing your comment.

[djct_watt]

Depends entirely upon your average speed and rates of acceleration/deceleration.

[SilverGlow]

Originally Posted by Loren

In theory, the tire with the larger diameter should give slightly better gas mileage. But, as Tamago points out, you need to be sure to correct your MPG calculations because the change in tire diameter is going to make the odometer inaccurate.

True, but at some point the MPG will actually go down over a smaller tire because as the size goes up, torque goes down.

In general, big tires do better for highway driving, and smaller for city driving because the smaller driving tires have more torque (pulling power) then larger tires....however for mostly highway driving (little stop and go) a bigger tire will provide better MPG, but again, only up to a certain size, then as the tire gets bigger MPG actually gets worse.