Wider tire on stock wheel (2011-2012)

[TheCPE]

I picked up a 2012 GT with the california package this week.

The stock tires are 245/45/19 on the 8.5 in wheel.

Looks like a 255/45/19 is fine on a 8.5 in wheel so I'm thinking of swapping to the larger tire. I'm actually a little surprised it didn't come with wider tires from the factory.

Has anyone else swapped to a 255/45 on the 19" stock wheels? If so what are your thoughts, do you have any pictures before/after?

I know it is only .4 " wider but the stock tires look a little skinny and I like the wheels so I don't want to swap them out.

Thanks

 

[Sparty92]

I'm sure you'll be just fine with that size. I have the Brembo wheel which is 9.0 inches wide. It came with the 255 tire. Personally, I don't mind a little sidewall bulge (you may see that). If you went to a 265 or 275 you might have an issue.

If you wanna be totally sure, go to tirerack.com and ask them what they think.

 

[TheCPE]

Using tire rack looks like every 255/45 tire is fine on a 8.5 inch wheel.

A 275 would be the perfect width I'm looking for but those require a 9 or 9.5 inch wheel.

Was hoping someone might have some 255s on with pictures to see if the difference is appreciable.

Thanks

 

[Az Pete]

I have always felt that the pros like to error on the safe side.....would like the 275's on my CS too....won't change the rims....why can't Ford look at the car from the rear.

 

[TheCPE]

Seriously!

My G35 had the same width tires on the rear as the mustang but they were only 18" diameter wheels so they didn't look as skinny and it only had 300 hp!

I imagine the 255 would look a little better...

Someone has to have 255s on 19s on a mustang out there they can post some pictures of from the rear.

 

[JKidd]

Seriously!

Someone has to have 255s on 19s on a mustang out there they can post some pictures of from the rear.

The Brembo package cars have just that. Not the best shot, but...:

 

[youngAR]

This is great info to know. Tire choices are already slim as it is.

 

[2010stangirl]

I too am wanting wider tires on the rear and have the same wheels/tires you do. I was thinking 265, but after reading this post, that may not be possible. I don't know if replacing the 245 with 255 is worth the money/time/effort for me.

 

[gtrules46]

A 275 mm would fit just fine. I have 8.5" bullitt wheels on my 93 coupe with 275 M/T drag radials on them & they are just fine.

 

[gtrules46]

275/40/17

Here's what they look like.I know it's not the same year, but I have a 2011 GT & am going with a 275 on the rear of those as well.

 

[Az Pete]

A 275 mm would fit just fine. I have 8.5" bullitt wheels on my 93 coupe with 275 M/T drag radials on them & they are just fine.

What is the entire tire size....sidewall makes a difference.

 

[gtrules46]

On mine it is a 275/40/17. My Nephew has a 2011 V6, base model. He found someone selling factory take off Brembo wheels for $750. The stock tires are 255/40R19's on the Brembo wheels, but the ones he bought have 275/40ZR19 on them. The stock 255's are really to narrow for these cars. You can give any tire shop a call & they will tell you what will work & what won't.

 

[gtrules46]

Side wall height

What is the entire tire size....sidewall makes a difference.

The middle number on a tire size references the percentage of the width that the side wall height is.

 

[Az Pete]

The middle number on a tire size references the percentage of the width that the side wall height is.

Yea....I missed the complete size in the title.....duh....

 

[Az Pete]

You can give any tire shop a call & they will tell you what will work & what won't.

That is where the questionable references are at for me. Tire shops just quote what the man. says.....which seem to be on the conservative side. I have not seen any place reference putting a 275 on an 8.5" rim. The entire reason for this post is keeping the stock GT/CS rims and getting a substantially wider tire on the rear.

In the past, I have pushed the width on the old school rims and cars. Having a taller side wall helps one accomplish that. With the 19's on the GT/CS, the side wall is short so there is less room for flex when fitting........

 

[Chuck H]

A 255/45-19 is almost the same as a 245/45-19. It should fit fine. If you wanted to go a lot wider, the next close diameter size for 19 inch wheels is 275/40-19. With the short sidewall on that size, though, it's only rated for 9-11 inch wide wheels, not 8.5 inch.

An alternative if you wanted to stay with 8.5 inch wheels would be 275/45-18. It's almost a perfect size match for your stock tires, but would require picking up some 18 inch wheels. And if you were going to get new wheels, you might as well get new 19x9 or 19x10 wheels.

 

[Az Pete]

The entire point is keeping the stock GT/CS wheels....

 

[SoldMySS4a5.0]

I basically had the same question. Gus from Steeda told me that I can put 285/40's on the stock 18" wheel (for Nitto Drag radials).

 

[Az Pete]

I basically had the same question. Gus from Steeda told me that I can put 285/40's on the stock 18" wheel (for Nitto Drag radials).

What is the width of your stock 18" wheel?

 

[SoldMySS4a5.0]

They've got to be 8 or 8.5 being stock coming with 235's