Advantages to 15" or 16" ?

Hey all,

I have a couple of questions on rim and tire sizes. I am about to replace the rims and tires on my truck, so help is needed for the decision. Mainly on the rim size.

Most people on the site have 15" rims, why? (price)or could I assume that the 15" is the best choice?

Wouldn't 16" rims provide less sidewall on the same inch tire verses the 15" rim? And wouldn't less sidewall provide more stability in cornering?

Why do the tire sizes "change" when you go from a 15" to a 16" rim? (eg: 31/1050R15 265/75R16 this is not an example of the same size tire just how they are advertised different)

Why can't the 16" be advertised in a 31/1050R16 format like the 15"s are?

I am very ignorant to tire sizing so take it easy on me.

Thanks,
Alan
98 Xplorer

 

[Guerilla Biscuits]

All I know is tires are cheaper with a 15" rim.

 

[donkey boy]

Alan, I'm trying to answer your questions:

Probably it's a kind of "cultural" thing. Here in the U.S., most SUVs come or came with 15', in Europe, 16' are more common.

I think the reason for most people having 15' is
a) Most Explorers coming with 15'
b) The big sizes 35'+ mainly being avaliable in 15'

Yes, a tire with the same overall diameter would have less sidewall with a 16' rim, what adds cornering stability, but what is not always desired when off-roading.

31x10.5-15 versus 265/75-R16. We are again at the "cultural" thing. 31x10.5 is the way you use(ed) to state dimensions in the U.S. 265/75 is the way we are used to in Europe.

Actually, the European way gives you the tire dimensions more accurate. Theoretically, it could be written as you say 32x10.5-16, but why should it? Actually, in the early 70ies, it's the U.S. that agreed to become metric

For more information, visit the page http://www.tirerack.com/tires/tiretech/truksize.htm

Alan, I hope this helps

[Edited by donkey boy on 08-14-2000 at 08:40 AM]

 

[ExplorGM]

Alan

I have 16" rims and tires on my truck. One disadvantage to the 16" is that there is less product available at this time than for the 15" sizes. This should change as more and more vehicles/Explorers use the 16" size. Most of the earlier Explorers came with the 15" size and 16" was offered as an upgrade, as on my Explorer. Larger wheels do indeed give you more stability/control on the
road as a result of shorter sidewalls (less flex), and more leverage for braking. Also a larger contact patch on the road given the same width.
I doubt if this will affect you, but sometimes one cannot go down in size because of disc brakes and the caliper/rotor sizes that the wheel has to fit around if there is much positive offset.
More flex might be wanted on the trail, and thus more sidewall to flex so the 15" wheel might be preferred, especially for the smaller diameter tires. Once you go over 33"-35" you've got quite a bit of sidewall to play with so it might not make as big a difference?
This is all layman's opinion. I am not an engineer so don't ask me for the mathematical formulas to back these ideas up!
Rick