Random Tire Question

[stng]

So I have a question for you guys about tire sidewall height. I have been looking at other peoples rides and I am noticing that a lot of guys go with a SHORTER side wall height on the REAR tires? Example 245/40/ZR17 on the front and 255/35/ZR17 on the rear. Why would someone do this? Woudnt it make the front of the car higher than the rear? It would seem to me that you would want it the other way around?

Thanks in Advance

Don

 

[wannabe2000GT]

it gives it a better rake so that the back is a tad higher than the front giving it the old school muscle car look. thats how mines setup

 

[03ghoststang]

well i run 245/45/17 out front stock size on a 17" rim
and 275/40/17 out rear on the stock rim ................but the overall diameter is close it is only off by a couple tenth of an inch like .05-.10 or so, the reason is the tire is bigger so with a 275 with a 40%(275/40) profile would be the same or close a 245 with a 45%(245/45) profile but it be wider giving it a better look

 

[tomustang]

the wider the tire, regardless of the sidewall height, will be taller

 

[triggz]

the wider the tire, regardless of the sidewall height, will be taller

That's incorrect, and simply not how tire sizing works.

a 245/45/17 tire is 25.68"
a 275/40/17 tire is 25.66" - significantly wider, yet slightly shorter.


stng, the reason you see a different, lower aspect ratio (middle #, the % of width that the tire will have in sidewall height) for the rear is because many people run a bigger tire out back. when the tire width (first #) increases, the aspect ratio must decrease to retain original overall tire height.

 

[Malevolyn]

I'd like to point out that, at least on my car and most SN95 Mustangs (V8, at least) I've seen, the rear is already higher.

 

[stng]

Thank You all very much... I have been wondering about that for a while but didnt want to look stupid by asking...

 

[tomustang]

That's incorrect, and simply not how tire sizing works.

a 245/45/17 tire is 25.68"
a 275/40/17 tire is 25.66" - significantly wider, yet slightly shorter.

ah, didn't see the different aspect ratios

 

[jimfitzgerald]

That's incorrect, and simply not how tire sizing works.

a 245/45/17 tire is 25.68"
a 275/40/17 tire is 25.66" - significantly wider, yet slightly shorter.


stng, the reason you see a different, lower aspect ratio (middle #, the % of width that the tire will have in sidewall height) for the rear is because many people run a bigger tire out back. when the tire width (first #) increases, the aspect ratio must decrease to retain original overall tire height.

This is the correct answer. Multiply the tire width by the aspect ratio to determine the sidewall height (in milimeters). Divide answer by 25.4 to get inches.