Mustang tire help

[KinLM]

So, here's my dilemma.

My 2012 V6 Mustang's Michelin Green-X tires are worn, and one now has a nail in it.

For a while, I've wanted to upgrade to higher performance, lower profile tires.

This would mean getting slightly larger rims most likely (I've wanted to do this anyways). I really am looking at rim size around 18 or 19 inch.

Problem is, I DO NOT want to throw off the speedometer with a different circumference tire.

I know I can compensate for a larger rim with a lower profile tire, but I have no idea what these measurements would be.

Is there a number on the tires that says their actual diameter? How can I figure this out? Would it be smart to ask somebody at a tire store? Or would they just try to talk me into purchasing another set of the High-profile Michelin green-x tires that I do not want?

Thanks in advance!

 

[Slash]

I have heard the V6 is under calibrated from the factory so upgrading to GT size wheels shouldn't make a huge even really noticable difference on the speedo or 'in the butt".

Tire diameter is the radial size number on the tire, in otherwords the number after the "R" in say 205/50R17.

As far as tire choice goes, if you are on a budget and want decent performance for the money, very popular Mustang tires for 350hp and under at the wheels are Cooper Cobra GT's and and BFGoodrich Radial T/A's. Both are all season tires but they are some of the "better" all seasons and provide very good perfomance for the price which is why you'll see them both on many Mustangs. Both are available with or without white letters.

 

[Crash]

Tire diameter is the radial size number on the tire, in otherwords the number after the "R" in say 205/50R17.

The 17 in this case is the diameter of the rim, or equivalently, the diameter of the inside circle of the tire.

You want to look at the "aspect ratio" to understand the height of the tire sidewall (so distance from rim to tread). Aspect ratio is the ratio of the sidewall to the tread width. In the above case, the aspect ratio is 50, meaning that the sidewall height is 50% of the tread width (205 mm), making the sidewall height 102.5 mm.

Add the sidewall height and rim size and you'll get the wheel's total diameter. If you go up in rim size and not impact the speedometer reading, choose a final combination as close to the original as possible.

Here's a good guide on how to read tire information.

 

[Slash]

The 17 in this case is the diameter of the rim, or equivalently, the diameter of the inside circle of the tire.

You want to look at the "aspect ratio" to understand the height of the tire sidewall (so distance from rim to tread). Aspect ratio is the ratio of the sidewall to the tread width. In the above case, the aspect ratio is 50, meaning that the sidewall height is 50% of the tread width (205 mm), making the sidewall height 102.5 mm.

Add the sidewall height and rim size and you'll get the wheel's total diameter. If you go up in rim size and not impact the speedometer reading, choose a final combination as close to the original as possible.

Here's a good guide on how to read tire information.

Thats what I was getting at. 👍

 

[Vegard]

disregard

 

[Ridox2JZGTE]

So, here's my dilemma.

My 2012 V6 Mustang's Michelin Green-X tires are worn, and one now has a nail in it.

For a while, I've wanted to upgrade to higher performance, lower profile tires.

This would mean getting slightly larger rims most likely (I've wanted to do this anyways). I really am looking at rim size around 18 or 19 inch.

Problem is, I DO NOT want to throw off the speedometer with a different circumference tire.

I know I can compensate for a larger rim with a lower profile tire, but I have no idea what these measurements would be.

Is there a number on the tires that says their actual diameter? How can I figure this out? Would it be smart to ask somebody at a tire store? Or would they just try to talk me into purchasing another set of the High-profile Michelin green-x tires that I do not want?

Thanks in advance!

I think this the correct size for your V6 Mustang OEM tire : 225/60R17

If you want to keep the speedo accuracy, I suggest to check your tire data here :

http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Energy LX4

Check the specs tab, and make a note of the rim width range, tire overall diameter and revs per mile. If you go to bigger wheel, there are only limited options on 18 and 19 inch wheel, as you will need to keep low profile and limited width on V6 Mustang. Do you care about tire life ? Any sort of price range ?

If you want the best handling in the dry with good wet grip, Bridgestone S04 Pole Position is perfect Good price at $161 for 255/45/R18 - similar diameter at 27.1". It has UTQG 280, while the Michelin has UTQG 500, so won't last as long as the OEM tire.

A bigger step up, 19 inch - closest tire diameter : 245/45/19 or 255/40/19. 245/45/19 is the closest in diameter to your 225/60/17 tire.

Bridgestone S04 PP 245/45/19 at $173, fitment for 2012 V6 Coupe Mustang

http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza S-04 Pole Position&sidewall=Blackwall&autoMake=Ford&autoYear=2012&autoModel=Mustang Coupe&autoModClar=Manual Transmission&partnum=445YR9S04PP&tab=Specs

OEM Michelin Energy LX4 225/60/17 at $149.

 

[TexRex]

With tires over 27", you're not looking at significant deviations from your displayed speed and actual speed anyway. Expect 2mph over in 5th at 3000rpm (with the standard 2.73 rear) with an increase of nearly half an inch--and that's with a displayed speed of 90mph. Of course you're probably not looking at a change that drastic. Even if you were, I'm pretty sure that on a vehicle that new it's just a matter of telling the computer about the tire diameter change.

 

[Slash]

With tires over 27", you're not looking at significant deviations from your displayed speed and actual speed anyway. Expect 2mph over in 5th at 3000rpm (with the standard 2.73 rear) with an increase of nearly half an inch--and that's with a displayed speed of 90mph. Of course you're probably not looking at a change that drastic. Even if you were, I'm pretty sure that on a vehicle that new it's just a matter of telling the computer about the tire diameter change.

I'm pretty sure its under-calibrated from the factory as it is.

 

[Grayfox]

Depends on country but normally it is up to 10%+2.5mph

On my civic which is from the UK it is
Speedo 25km/h, Real 24km/h
Speedo 50km/h, Real 48km/h
Speedo 75km/h, Real 72km/h
Speedo 100km/h, Real 96km/h

But each car has its own variation, check with a GPS and compare if you can so you can get a better baseline