Rear Tires

[RyfleMach]

Currently my vehicle is stock except for a whipple stage 1 and double x pipe resonator delete. I’m tired of the cup 2s already as I use my car as a daily. I want to swap out to Michelin pS4S which I know are good tires, but I’m debating as to how wide I can go. I’ve seen some people go with 325/30r19’s and be fine, but I’d like to get to 335 or 345s if possible. I have the handling package, and I don’t want to change anything suspension wise. What’s the max I can run on 19’s without rubbing and also keeping my Speedo reading decently accurate?

Sponsored

 

[Hi-PO Stang]

That number 1 on your car sure looks good. Best addition I have seen on a Mustang this year. I hope you find tires you like.

 

[young at heart]

I can’t help with your tire question and in fact I’d like to know myself.

I can tell you though that your “stock except for a Whipple” comment caused me to spew coffee on my keyboard. Consider yourself the master of understatement!

And great looking car!

 

[WItoTX]

Welcome to the forum.

Tirerack has all the dimensions for tires. Start there. It's an 11" rim if I recall, and generally you want to be the same width or slightly less wide to keep the car responsive. Go too wide, it will feel sloppy. I'd hazard a guess you will be way too wide with a 325, and will hinder it's performance. Your call.

Assuming you have the 1 on the side for some sort of track duty, you are going to hurt your car's performance by going any wider.

 

[Charlemagne]

It's about the rim. Recommended for 11" is 305 mm and 315 mm in profile 30/35, 325 mm still works.
11.5" has recommended 325 mm and 335 mm in profile 30/35.
12" has recommended 335 mm and 345 mm in profile 30/35.
I wouldn't go with wider than 325" on 11" rim, it would bulge. For performance tires small stretch is better instead.

11" HP rim has plenty of space inside and outside it's pretty much flush.
I can imagine 11.5" ET 50-52, it would fit fine: https://www.1010tires.com/Tools/Wheel-Offset-Calculator

It's about the tread width more than about tire width, it's entirely possible that 345 wouldn't provide any benefits to the driving than 315-325. Grip is fine on those anyway.

As for diameter difference, go here: https://tiresize.com/tyre-size-calculator/
335/30 has +1.9% difference from 315/30, that's fine, 345/30 has +2.7% which is still usable.

 

[RyfleMach]

I don’t mind getting new rims, so if it fits I’m willing to do it.
I’m also curious if I should go with drag tires instead of the PS4S. I haven’t been able to launch my car well yet, so I honestly don’t know how traction will be with them, especially since it’s cold where I’m at right now.

 

[Mikepol2]

Depends what you're after. Our cars tend to understeer in corners so ideally you want more grip up front than in the back, but if you're just going for straight line hookups it's probably more a tire compound than width issue.

 

[NJMike]

I don’t mind getting new rims, so if it fits I’m willing to do it.
I’m also curious if I should go with drag tires instead of the PS4S. I haven’t been able to launch my car well yet, so I honestly don’t know how traction will be with them, especially since it’s cold where I’m at right now.

Can you provide a little more insight on how you intend to use the car? Is it a daily driver? What type of weather conditions?

If its not daily then straight line, corner carving or both? these things help us help you

EDIT - Had I remembered what you wrote in the first post, I'd know its a daily driver. With that, you probably will end up off roading a bit if you chose drag tires.

 

[RyfleMach]

Depends what you're after. Our cars tend to understeer in corners so ideally you want more grip up front than in the back, but if you're just going for straight line hookups it's probably more a tire compound than width issue.

I’m looking for straight line hookup. I daily drive it, and I like going fast in a straight line. If I had the option to take it to the track or a drag strip, I’d pick the latter any day.

 

[luc]

I’m looking for straight line hookup. I daily drive it, and I like going fast in a straight line. If I had the option to take it to the track or a drag strip, I’d pick the latter any day.

Nobody is perfect

 

[Mikepol2]

Then in addition to tires suited for hooking up you may want to consider something like this or something similar from Steeda, among other things:

https://www.bmrsuspension.com/?page=products&productid=1543

 

[RyfleMach]

Then in addition to tires suited for hooking up you may want to consider something like this or something similar from Steeda, among other things:

https://www.bmrsuspension.com/?page=products&productid=1543

Sorry, I’m not aware of what those do. I looked it up real quick but still don’t understand it lol. I can see it reduces the cradle bushing deflection but idk what that means in English.

 

[Mikepol2]

Sorry, I’m not aware of what those do. I looked it up real quick but still don’t understand it lol. I can see it reduces the cradle bushing deflection but idk what that means in English.

Less wheel hop and better traction at launch. Lots of threads on things like this, or I am sure other people in this thread, who have used things like that could chime in.

 

[Rick#7]

Depends what you're after. Our cars tend to understeer in corners so ideally you want more grip up front than in the back, but if you're just going for straight line hookups it's probably more a tire compound than width issue.

^ This!
Contrary to popular belief, simply putting a wider tire on does not guarantee increased traction. Tire type and quality have as much or more to do with traction than size. What many people seem to forget, is that the size of the contact patch of the tire ( the area of the tire in physical contact with the road) is determined entirely by the weight supported by the tire and air pressure in the tire. You can put as big a tire on the car as you want, but if you put the same air pressure in it as the stock tire, and the weight of the car didn't change, that huge tire will have the exact same size contact patch as the stock size tire. The only thing that changes is the shape of that patch. That in and of itself, can affect the traction, but more so in handling than in a straight line drag launch. Typically, for drag racing you want to maximize the area of the contact patch. This is done with lower psi in the tire, moving weight in the car from the front to the rear (i.e. relocating the battery to the trunk), and suspension changes to enhance weight transfer when launching and to plant the rear tires. The difference in contact patch shape by going from a 315 to a 335 or even 345 will have very little affect on drag traction compared to these other changes.

Also, all else being equal, you'll see much better off the line grip with a summer tire and 200 treadwear than you would with a 500 treadwear all season tire. You'll get even better grip with a drag radial, hands down. You might want to consider going with an 18" rim on the rear and increasing the sidewall ratio to maintain overall tire height. The taller sidewall seems to work better in drag applications.

 

[swoop1156]

I went with 325's in the rear just because I could, they look good, and at my time of purchase, they were cheaper than the 315's. Running them on the factory 11" HP wheels.

Sponsored