Which wheel offset to eliminate spaces

[carlg]

I cannot stand the factory offset of the wheels on the S550 Mustangs. I feel like the wheels should be aligned more to line up with the fenders or at least close.

The eliminate this I added 1 inch spacers to the factory California Special wheel.

It now looks perfect!!

If I was to shop for new wheels, what offset would I look for so I can get the same effect and not need to use the spacers?

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[ripto]

I don't know much about wheels, but wouldn't the offset you'd look for be equal to the width of your spacers?

I plan to do the same thing when I swap back to my summer setup, but I am concerned about more rock chip damage on the paint right behind the wheels.

 

[66Bronc1]

This is a great question and one I often ask on other make cars I have owned. If you look on Tire Rack there are so many different wheels available. There are many different offsets and also widths available too. More offset moves the wheel inward and less offset moves the wheel outward. It gets more complicated with the different widths.

The way I calculate it is to look at the stock wheels and the way they fit in the wheel wells. Then determine the wheel width and offset (They should be stamped on the inside of the wheel). Then look for the same width wheels in a catalog or on Tire Rack and look at the different offsets- subtract the offset of the stock wheels from the new wheels and that is how much more they will stick out. The offset is in MM so you will need to convert it to inches.

For a different width wheel, it gets more complicated. You will need to determine the offset difference then add 1/2 of the difference between the widths of the wheels.

Then it's up to you personal preference as to how "flush" you want the wheels to the fenders. Some like more of the positive offset with the wheels inward and some prefer more of a negative offset with the wheels outwards. Aftermarket wheels only vary be a few MM in offset but that little bit can make a big difference in appearance.

 

[carlg]

This is a great question and one I often ask on other make cars I have owned. If you look on Tire Rack there are so many different wheels available. There are many different offsets and also widths available too. More offset moves the wheel inward and less offset moves the wheel outward. It gets more complicated with the different widths.

The way I calculate it is to look at the stock wheels and the way they fit in the wheel wells. Then determine the wheel width and offset (They should be stamped on the inside of the wheel). Then look for the same width wheels in a catalog or on Tire Rack and look at the different offsets- subtract the offset of the stock wheels from the new wheels and that is how much more they will stick out. The offset is in MM so you will need to convert it to inches.

For a different width wheel, it gets more complicated. You will need to determine the offset difference then add 1/2 of the difference between the widths of the wheels.

Then it's up to you personal preference as to how "flush" you want the wheels to the fenders. Some like more of the positive offset with the wheels inward and some prefer more of a negative offset with the wheels outwards. Aftermarket wheels only vary be a few MM in offset but that little bit can make a big difference in appearance.

Thanks!!

Would all of our factory studs be in the same location? So although you can use your current wheels and calculate a difference, shouldn't you also be able to calculate it from the factory stud position?

 

[MaskedRacerX]

There are a ton of aftermarket options where the wheel has been properly designed based on width/offset/backspace. FWIW, I found 1" spacers a bit too much on PP wheels, I ran 25mm (front) and 23mm (rear), just slightly under 1" (but as small as you can go without contact on the stud pocket with Perf Pack wheels) and even those were a _touch_ too much.

My current setup is fantastic, 20x11 @ 50mm offset, 20x10 @ 35mm, they sit nearly flush, with just the right amount of inset to avoid rubbing and reduce the amount of crap kicked up on the side of the car.

Oh yeah, just to show how it sits vs. the rear 19x9.5 OEM PP wheel: it's 21mm further out (which should give you a sense vs. 23, 25 or 25.4mm spacers). Now of course since it's 1.5" wider (38.1mm), and 21mm is to the outside (of the wheel center), the other ~17mm is on the inside, and this where a properly designed wheel makes the difference since you have to consider clearance to the strut, etc.

Also, I obviously made the leap to a totally different tire setup as well, so that's a factor if you're trying to keep your OEM size tires or OK with replacing (I didn't want just more offset, I wanted a wider wheel/tire setup).

Sorry about the incremental edits, I'm also neck deep in some complicated code - anyway - final couple of things: get into the wheel tech area, there's a ton of good information, plenty of super helpful wheel vendors that can give you excellent information, PK Auto, MRR, etc.

... and lastly, because, you know, it's worth a 1000 words

 

[TigerFire13]

From what I can find, the GT/CS wheels are a square setup(?), 19x8.5+42.5, running 255/40/R19 tires?

If that is correct, and you just want to eliminate the spacer, you would convert the 1 inch spacer to 25.4 millimeters, and subtract that from the +42.5mm offset of the GTCS wheel. That would net you +17.1, or basically 19x8.5+17. 8.5 is an interesting width. If you choose to go with a different width wheel, That changes the offset like 66Bronc1 said. A 19x9/20x9 wheel would have a +23 offset, and a 19x10/20x10 wheel would have a +36 offset.

All of the previous values are dependent on your GTCS wheels having a 19x8.5+42.5 size all around, AND your spacers being exactly one inch. If either of these are not true, you will have problems with the above information.

 

[66Bronc1]

Thanks!!

Would all of our factory studs be in the same location? So although you can use your current wheels and calculate a difference, shouldn't you also be able to calculate it from the factory stud position?

The bolt pattern of the studs should be the same for all S550 Mustangs.

 

[Grintch]

For a 10" wheel you want to be around +35 to 40. The true ideal is a little different front and rear, and also varies with how much camber you run (more camber needs less offset).

And if you are buying new wheels, I wouldn't bother with buying anything smaller than a 10" wide wheel. Bigger than 10" requires an non square setup with different offsets front and rear.

 

[Bluelightning]

I run 20x9.5 with a 40 offset on the front, and a 20x11 with a 50 offset in the rear. You can check out my garage and see how they look.

 

[VooDooDaddy]

I am currently running American Muscle Performance Pack replica 19"x10" wheels with a 7.4" (188mm) backspacing wearing Nitto 305/35-19 rubber on the rear of my 2016 GT.

On the front I also have American Muscle Performance Pack style 19"x8.5" wide wheel with a 5.93 (151mm) backspacing wearing the stock 255/40-19 rubber combined with 25mm wheel spacer. This combo paired with BMR lowering springs give my car a perrrrfect stance, and fits the wheels/tires flush with the front and rear fenders.

Wish I had a better picture to post...

 

[TURTL3]

https://www.willtheyfit.com/

Helps you calculate the differences in your current and prospective wheel setups. The offset you want depends on wheel width and tire width. I would go to the wheel thread and poke around and see which setups you like to get an idea:

https://www.mustang6g.com/forums/th...ith-aftermarket-wheels-and-tires.15709/unread

 

[MaskedRacerX]

19x8.5 ET42.5

Wish I had a better picture to post...

That's a __great__ photo, really captures some of the lines you don't normally see - I especially love seeing the side strake continue from the front fender, across the door, and then get picked back up at the back of the rear fender.

 

[NightmareMoon]

For an 11" wide wheel, ~ET50 offset. For a 10" wide wheel, try a ET35 offset. IDK about 9 or 9.5" wheels, I don't run those

 

[VooDooDaddy]

19x8.5 ET42.5


That's a __great__ photo, really captures some of the lines you don't normally see - I especially love seeing the side strake continue from the front fender, across the door, and then get picked back up at the back of the rear fender.

Thank you. I think the Ingot Silver color really shows the contrasts created by the body lines. I have seen other colors that don't do that very well. I saw a red S550 last week and that color blends the body lines into the body of the car, not accentuate them. While I'm not saying that red car was in any way "ugly", it just made the body lines harder for the eye to pick up.

 

[LSchicago]

https://www.willtheyfit.com/

Helps you calculate the differences in your current and prospective wheel setups. The offset you want depends on wheel width and tire width. I would go to the wheel thread and poke around and see which setups you like to get an idea:

https://www.mustang6g.com/forums/th...ith-aftermarket-wheels-and-tires.15709/unread

The silver/BAP combo looks great. Never seen one before.

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