2010 Mustang GT - Staggered tires

[Nelson Valdes]

Hey everyone,

I had a question regarding tires on my 2010 Mustang GT. I have stock 18x8.5 rims and the car has P235/50-18 Goodyear Eagle Asymmetric F1 tires on it. I just bought a set of P255/45-18's for the rear but really didn't get the look I wanted as the height of the rear tires still look smaller than the front. My car is a little high in the rear end so that doesn't help as well. I was wondering if I could put a set of P275/45-18's on the back and move the 255's to the front. Any one have experience with this setup. Will I still get that short height look and I'm worried about rubbing as well. Also, will the rear tires bulge to much and possibly create handling issues. Many thanks in advance!

 

[Pentalab]

My 2010 GT came with 8" rims..and 235-50-18's. Are you certain you have 8.5" wide rims ?

 

[Nelson Valdes]

My bad, I checked and the car has the silver five spoke rims and yes, they are 18x8. Thanks for clarifying that!

 

[Pentalab]

I use nitto Motivos' in 235-50-18 on all 4 x corners for fall / winter..excellent rain tire. (On oem 18 x 8 rims) Motivo's run wide.

For spring / summer I now use AM chrome bullitt rims, deep dish..... 285-40-18 on fronts... using a 18 x 10 rim ( 45mm offset on rims....and a small 3 mm HR hubcentric spacer. Effective offset is now 42mm.

Rears are MPSS 305-35-19.... using a 19 x 10 rim...with a 48mm offset. It really should be on a 10.5 to 11.0 rim.

I have tried other combo's in recent past summers. Like 275-40-18 rears on 18 x 10 chrome bullitt rims...and a 255-45-18 on 18 x 9 rims on the front. Worked good, handled good. Fronts are stretched 1/2".

Then used 285-40-18 rears and 255-45-18 fronts. Works superb. Then both front + rears are identical diam.

Then tried 285-40-18 rears.... and 275-40-18 fronts. This was a dud. The 275-40-18's were on 18 x 9 rims. Handling was un-responsive and sluggish. I hated it.

Then tried 285-40-18 rears.... and 275-40-18 fronts... but this time front rims were 18 x 10. Handling was superb.

Then tried the current config... with 305-35-19 rears..and 285-40-18 fronts.

If I was doing this from scratch... I'd use 285-40-18's on both front + rears.... on 18 x 10 rims ( I measured tread width at 10.0" ).

275-40-18's, also on 18 x 10's...for front and back is a good combo. ( measured 9.5" tread width)

With a square setup you can then rotate front to back. I'm not impressed with the staggered look.
I have to lay on the grnd to even see the stagger.

On oem 18 x 8 rims.... don't use anything but 235-50-18's for rubber.
You can get away with ur proposed 255-45-18 on oem rear 18 x 8 rims...just.

If u use the 255-45-18 on the front oem 18 x 8 rims... the handling will be sluggish and un-responsive.... but usable.

Don't even think abt a 275-40-18 on oem 18 x 8 rims. Bare min width for a 275-40-18 is a 18 x 9" rim.

 

[Nelson Valdes]

Great information! I really appreciate it! Any other thoughts out there are welcome Thanks again!

What about 245/40-18 for the front and I have the 255-45-18 on the rear?

 

[Gabe]

What about 245/40-18 for the front and I have the 255-45-18 on the rear?

That front size is 25.7" tall and the rear would be 27".
That alone will make the front sit about .6-.7" lower than the rear.
I would not use that front size, too short for a Mustang.

Also, a 275 is way too wide for an 8-8.5"-wide wheel.
It fits perfectly on 9.5-10"-wide wheels.

 

[Norm Peterson]

What about 245/40-18 for the front and I have the 255-45-18 on the rear?

245/40-18 is really too small from a rated load point of view at either Load Index 93 in Standard Load or 97 in XL. While you can compensate for small differences in load index by varying the inflation away from the door-sticker number(s), you'd need to be out at 37 psi or so in 245/40's just to match the OE tires at 32 psi. That's past the tabulated inflation pressures that a Standard Load tire is even rated to, and harder riding for no benefit in XL (that's good out to 42 psi).

I'm far less bothered by 245/40's being shorter than 26" than I am about the load capacity issue. I'm running 25.9" tall tires for road course driving (and for a fair amount of street driving when I get too lazy to swap them out for the street set).


I suspect that the different sheetmetal shapes and clearances, front vs rear, are mostly to blame here for the 255/45 rear vs 235/50 front appearance.


For several years I ran 255/45-18 Asymmetrics (the original Asyms) on 18x9.5 GT500 wheels. Same wheel and tire size as the 2008 GT500 fronts except all around. 27" tall.


Car was at stock height when the above picture was taken.

The next size I put on the GT500 wheels was 265/40-18, definitely shorter at about 26.3". But by the tme this picture was taken I'd lowered the car by a little over 1/2"



Pentalab has given you a lot of good advice.


Norm

 

[Nelson Valdes]

I have the 255/45-18's on the back and they fit very well. No bulging at all. I was reviewing the Goodyear website and I was rethinking to 235/40-18's for the front. Obviously this varies pre vehicle but their chart says that all these tires are compatible with 8 inch rims. What do you think about the 235/40-18's for the front? The diameters would be 27" on the back and 25.4" on the front. That way the rear tire doesn't look taller. I attached pics of my car. As you can see the front stock tires look taller than the 255's on the back. The side view not as much but when you see it in person the fronts look taller. Once again, I appreciate all of your replies. You guys are helping me a great deal!!!

 

[Nelson Valdes]

That front size is 25.7" tall and the rear would be 27".
That alone will make the front sit about .6-.7" lower than the rear.
I would not use that front size, too short for a Mustang.

Also, a 275 is way too wide for an 8-8.5"-wide wheel.
It fits perfectly on 9.5-10"-wide wheels.

Beautiful Mustangs Gabe! Thx for the reply!

 

[Norm Peterson]

I have the 255/45-18's on the back and they fit very well. No bulging at all. I was reviewing the Goodyear website and I was rethinking to 235/40-18's for the front. Obviously this varies pre vehicle but their chart says that all these tires are compatible with 8 inch rims. What do you think about the 235/40-18's for the front? The diameters would be 27" on the back and 25.4" on the front. That way the rear tire doesn't look taller. I attached a pic of my car. As you can see the front stock tires look taller than the 255's on the back. Once again, I appreciate all of your replies. You guys are helping me a great deal!!!

View attachment 70203

Trust me, it bulges (by a little more than 1/2" on both the inside and the outside, and it's obvious enough to me just looking at your picture that they bulge). All minimum-recommended and even "measuring-width" wheel to tire fitments do. Don't use what the OE tires and wheel fitments on standard sedans, SUVs, crossovers, or pickup trucks look like as a reference for what a performance wheel & tire fitment for a performance car should look like.


You need to pay more attention to load ratings - that "Load Index" thing - and less to diameter differences between front and rear. Make your car functionally correct before you try to make it look some certain way.


Norm

 

[Nelson Valdes]

Thx again Norm! By the way nice Stang!

 

[frank s]

I believe tire diameter has less to do with perceived "filling of the fender wells" than does lowering of the body over the axles (drop). If what the OP is looking for is "handling" performance, his wheels are not adequate for any useful improvements.

 

[Nelson Valdes]

Thx for the input Frank!

 

[Norm Peterson]

I believe tire diameter has less to do with perceived "filling of the fender wells" than does lowering of the body over the axles (drop). If what the OP is looking for is "handling" performance, his wheels are not adequate for any useful improvements.

I think that depends on whether the viewer is looking only at the tire to sheetmetal clearance as a linear dimension at the tops of the tires, or at how much of the sheetmetal opening is filled by wheel and tire on a side view area basis.

From what I read on most forums, most folks seem only concerned with the tire to sheetmetal gap at the tops of the tires. That the wheels are clearly uncentered in the opening and the tire to sheetmetal gaps down at the bottom of the bodywork have gotten wider is like, invisible.


Norm

 

[Mackitude]

Use this site to check for changes in sidewall/overall height, as well as speedo error

https://www.americastire.com/learn/tire-size-calculator

 

[Norm Peterson]

Use this site to check for changes in sidewall/overall height, as well as speedo error

https://www.americastire.com/learn/tire-size-calculator

Don't be surprised when the revs per mile calculated by that little app do NOT line up with tire mfr revs/mile data even if the mfr's "tire height" is exactly the same as what Discount Tire's app calculates it out to be from the tire size designation.


You can expect the app to be about 3% to 3.5% off (on the low side), where 800 revs/mile calculated by the app turns out to be 824 - 828 revs/mile. For most purposes, it's not worth worrying about . . . but shame on Discount Tire for overlooking a tire property when it's their business to know about tires.


Norm