Hello Mustang peeps. My 2019 came with 20" wheels and 265/35R/20 all season Yokohama's. Been tracking it (Limerock Park, CT) lately and want to move to a wider wheel/tire setup (not staggered) and wanted to ask if anyone knew the limit in terms of width I could go. Thinking move to 19" rims and perhaps 275's or 285's all around but not sure of the fitment nuances...if any? Any insight is much appreciated. Thanks all and be well.

 

I believe you can fit 11" wide wheels with 305 tires, if everything is just right; meaning perfect offset and you might need some extra negative camber in the front. (which you want for the track anyway)

A more forgiving fitment might be 10.5" wheels or 10" wheels, which won't be so critical on everything for clearance. Again the offset needs to be correct, and I am not sure of the numbers for the S550 chassis.

After you have selected the wheels, you want to size the tires to fit the wheels. You can look up specific tires on Tire Rack, and check the "specs" tab to see the manufacturer's recommended wheel rim width range for that specific tire. You want the wheels to be at least the "measuring width" or better yet, the widest wheel for that tire. That will give you the biggest contact patch from that tire size, and also keep the handling nice and crisp. I think 275 tire is good for a 10" wheel and 285 or maybe 295 for a 10.5" wheel, but I would check the tire manufacturer's recommendations to make sure.

In the past 18" wheels were the go-to size for track cars due to wheel weight and tire availability and pricing; but lately 19" seems to be better for tire availability and not much higher on tire cost than 18" and only a little heavier than 19." While you are buying wheels, pay attention to the weight, the lighter the better as long as you don't compromise structural integrity.

Vorschlag used to be about the best I know for wheels with extreme/correct fitment for these cars, but I'm not sure they sell them any more (maybe just Forgestar they do not sell any more?). I'd check Vorschlag first, and then probably Steeda, to see what they recommend and find out what is the correct offset.

 

Thank you so much Bert! This is exactly what this rookie needed and will circle back with an update once I work this out...or more likely with more questions!