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Discussion Starter · #1 · (Edited)
Decided to post it here because it's something that a lot of people probably know the answer to.

Wheel weight aside (8" wide vs. 10" wide). What has less rolling resistance?

1. A 35 x 12.5 R15 tire on an 8" wheel at tire pressure which yields a flat tread pattern. (it will take less psi to get it to be a flat pattern, right?)

or

2. A 35 x 12.5 R15 tire on a 10" wheel at tire pressure which yields a flat tread pattern. (it will take more psi to get it to be a flat pattern, right?)

My instinct tells me that the 8" wide wheel will have less rolling resistance, even though it will be lower psi than the 10" wide wheel.

Any thoughts?

~Miguel
 

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Get the 8in wide wheel. You will get better MPG and better tire life. I had some 10in wide wheels once but they ate MPG and tires but they were awesome offroad. So choose whichever suits your needs.
 

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don't know for sure but I think the 8" has less still. also, if you are choosing between the two, get the 8" your truck isn't tall or big enough (which is good) for the need of wider rims... 8" will be better for you IMO.

-Alex
 

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Discussion Starter · #4 ·
don't know for sure but I think the 8" has less still. also, if you are choosing between the two, get the 8" your truck isn't tall or big enough (which is good) for the need of wider rims... 8" will be better for you IMO.

-Alex
It's not for my truck as it is. It's for my truck after the SAS.

~Miguel
 

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in that case... I run 15 x 10 rims and feel much more sturdy and confident running them instead of 15x8's granted i have 37's and am kinda tippy..:rolleyes: how much lift will your truck be running on when completely done?

-Alex
 

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Discussion Starter · #6 ·
in that case... I run 15 x 10 rims and feel much more sturdy and confident running them instead of 15x8's granted i have 37's and am kinda tippy..:rolleyes: how much lift will your truck be running on when completely done?

-Alex
I'm talking about rolling resistance. This is my DD and I need to feel somewhat good about myself for at least TRYING to get it to be a more practical vehicle.

I'm gonna be using 44044s...possibly with a leaf pulled.

~Miguel
 

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does anyone have a pic of how a tire on a rim looks thats 37X12.50X15 on a 10" rim?
 

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I'm not a physics engineer but IMHO the resistance would be the same because your footprint is still the same. The amount of rubber touching the road is going to be your determining factor on resistance/friction. If you wanna get down to brass tacks the only difference I can see is that an 8" rim might require about .4 psi less to achieve the same footprint, but unless your using nitrogen, your psi is going to vary too much by temperature differenciation for that to affect your MPG.
 

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I'm talking about rolling resistance. This is my DD and I need to feel somewhat good about myself for at least TRYING to get it to be a more practical vehicle.


~Miguel
LOL...good luck with that:)

Hey Miguel, Like Sgt said...I'm no super expert but I agree with what you orginally stated. However, I think the difference between the two rims for MPG will be insignificant. If it was me, I would base it more on your prefernce for looks and on/off road performance then the very slight MPG you may or may not gain.

-Will
 

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I don't know either, but my guess is the wider rim with higher pressure will have less rolling resistance, based on 2 lines of reasoning. One is that where the energy goes seems to primarily be into flexing the rubber, so you want the one with less flexing as it puts its footprint on the road. The other is experience with bicycle tires, where 120psi is less rolling resistance than 100psi, even though visually the difference is tiny.

However, I agree with others that you should probably not worry about this too much. When you push your truck on a flat surface, the first thing you feel is inertia, then you feel mostly tire rolling resistance to keep it at constant speed. Once you get to daily-driver speeds, other resistances swamp out this resistance. (Although, on the other hand, they do say that a couple of psi is good for some mpg). And most likely the wider rim will have negligible effect on air drag.
 

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Discussion Starter · #11 ·
LOL...good luck with that:)

Hey Miguel, Like Sgt said...I'm no super expert but I agree with what you orginally stated. However, I think the difference between the two rims for MPG will be insignificant. If it was me, I would base it more on your prefernce for looks and on/off road performance then the very slight MPG you may or may not gain.

-Will
Haha! Yea, I know I'm entering a world of shit, but hey, our local mall has just installed 3' curbs and they're BEGGING to be ramped.

In all seriousness, my commute is a mere 5 miles each way so I think I can deal with that. I'll buy a Vespa if need be. :D

~Miguel
 
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