Rims + tires Question

[theSpoon]

Hi, I'm planning on buying some suv rims from a friend that are 15x7 5x4.5 And I have a 97 explorer sport with the 255/70R16 rims on it. What I need to know is what size tires I need to replace the old ones to have the same size tire i have now. I don't know what the 255 means so I'm at a bit of a loss here. would it just be 255/70R15? Also I will go larger if needed but idk what to do about speedometer/odometer then.

 

[iaml3lue]

i used http://www.miata.net/garage/tirecalc.html to figure this out if you want to stay with same with a 255/75 r 15 will be spot on a 275/70 r15 will be .2 inches biggger but also be slightly wider an a 305/60 r15 will be .5 inches bigger but a hell of alot wider i hope this helps

 

[theSpoon]

thanks i think i got it now. since i was going down in a rim size i wanted to get tires to fit as close to stock as possible. I'd just replace my rusty old 16 inchers with another set of 16's but my friend gave me such a deal and my tires are worn out anyway.

 

[FROADER]

A 255/75/15 Will be the exact same height and width.

255/70/16 = 30.1x10 with a 7" sidewall
255/75/15 = 30.1x10 with a 7.5" sidewall

 

[theSpoon]

its actually not 7.5 i dont think
thats a 5x4.5 bolt pattern? im not sure exactly but they're too separate numbers

 

[FROADER]

its actually not 7.5 i dont think
thats a 5x4.5 bolt pattern? im not sure exactly but they're too separate numbers

It actually is 7.5" of sidewall on a 255/75/15.
You asked for the same size tire from a 16" wheel to a 15" wheel. That's the size I gave you.

And... uhh... what do the bolt pattern numbers have to do with what I posted?

 

[theSpoon]

sorry i thought you mighta thought the 5 was with the 7, i really don't know much about this whole tire size thing. i just want to have my speedometer read the same, and have the tires fit without modifications.

 

[Duster Doug]

hi all - just wondering about a similair issue I'm having.

I have a chance to get some free Ford EX 16" stock rims with larger 255/70/16 tires for my 2000 XLT which currently has 15" stock rims with 235/75/15 tires.

Would I be able to replace my 15" rims/tires with the 16" rims/tires without speedometer issues/ concerns??

thanks in advance

 

[gmanpaint]

Ford went to 16" wheels for larger brakes. Stock 15" to 16" is not a problem for the brakes. Stock 16" to 15" would be an issue, as the calipers would rub the inside of the wheel.

Speedo & Tires:
Inside diameter is not a concern, the Outside diameter is what matters for speedo concerns. As long as the OD is the same, there is no change in speedo ratios. The larger the tire, the less revs in a mile, the smaller the tire the more revs in a mile.

Going to a larger tire will affect your Speedo. This is not a problem for vehicles with a VSS gear. A simple swap of the gear ($3.00 & 5 mins) to correct. Vehicles (98+) without a VSS gear, need to have the speedo corrected with a special flash from a dealer or shop with a special electronic tool. Around $100.