2005 Mustang Tire change Question

mozstang · 03-07-2008

I have 215/65-16 original tire/rim size on 2005 Mustang convertible and would like to replace them with original 235/55-17 2008 Mustang GT rims and tires. Are there any concerns I need to know about doing this?

John

psychobenz · 03-08-2008

your speedometer will be off by a bit, easily fixed with a tuner or you can go to the dealer and they will fix it for like $50. and there is something called a steerstop which also needs to be changed. there is a specific one for 16'' rims, another for 17'' rims, and so on....

06sixbanger · 03-08-2008

Youre gonna need a balance and alignment as well.

**stlwagon** · 03-08-2008

Quote:

Originally Posted by 06sixbanger

Youre gonna need a balance and alignment as well.

Why an alignment? He's not changing the geometry on anything.

mozstang · 03-08-2008

Thank you for the information. I understand the tuner from the dealer and it's always good to get your wheels balanced, but what is a steerstop?

mozstang · 03-08-2008

Did a little more research and found out that the steer stop is a bolt located behind the front wheels that dictate steering clearance left and right. Depending on your rims and tire choice you may need to adjust this with spacing washers to prevent rubbing when turning. But many Mustang owners on this site have indicated that they have not had to make adjustments when upgrading beyond the tuner portion for correct speedometer reading.

Thanks

**stlwagon** · 03-08-2008

Quote:

Originally Posted by mozstang

Did a little more research and found out that the steer stop is a bolt located behind the front wheels that dictate steering clearance left and right. Depending on your rims and tire choice you may need to adjust this with spacing washers to prevent rubbing when turning. But many Mustang owners on this site have indicated that they have not had to make adjustments when upgrading beyond the tuner portion for correct speedometer reading.

Thanks

You need to compare tire revs/mile to determine how far off your speedometer is going to be.

mozstang · 03-09-2008

Thanks, I will let you know the results soon.

ckrebel910 · 03-09-2008

your spedometer should only be off by about 1 mph when at 60 mph. It's not a big enough difference to worry about. don't waste your money on a tuner unless you actually want to tune it.

ckrebel910 · 03-09-2008

It will be off by .5 mph when you are going 65 mph. When your spedometer reads 65 you will actually be going 65.5 mph. Your spedometer could originally be as far off as that much form the factory... It's not a big deal.

psychobenz · 03-11-2008

just to remove any doubt, here is the tire size calculator.

Tire size calculator

mozstang · 03-11-2008

Thanks.

Based on everyone's help and some info from Ford, I will not be adjusting the steer stops or the tuner (tune $80 at a dealer) since it will be minimal change.

I will post a pic when complete.

psychobenz · 03-11-2008

glad we could help.

kn0x` · 03-11-2008

will 255/45/18 fit on my v6 without the tire sticking out either.

ckrebel910 · 03-12-2008

If those are the GT optional wheels they won't stick out. Those are tire dimensions. If you're concerned about the wheels sticking out, you need to check the back spacing. Look for "proper spacing for 05-08 Mustang". You're also getting into territory that it might affect your spedometer, some people don't care about that though. If you have ABS it's been said that you shouldn't go more than 2 inches larger in wheel diameter or it's bad for the car, just some extra info.