20" OEM wheels

[Tr33s]

I just bought a 2020 GT that came with the 19" black out edition wheels. They are 9" wide wheels with 255/40/19 tires. I'm looking at upgrading to 20" wheels and I found an OEM set from a 2017 GT and they are 9" wide with 265/35/20 tires. The tires that are on the 20's are shot and will need replacing and I want to know how wide of a tire can I safely put on the 20's, front and rear with no chance of rubbing or effing up the stock diameter ratio too much?? The car is at stock ride height and I have no plans on lowering it. Thanks!!!

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[jsquires4]

I just bought a 2020 GT that came with the 19" black out edition wheels. They are 9" wide wheels with 255/40/19 tires. I'm looking at upgrading to 20" wheels and I found an OEM set from a 2017 GT and they are 9" wide with 265/35/20 tires. The tires that are on the 20's are shot and will need replacing and I want to know how wide of a tire can I safely put on the 20's, front and rear with no chance of rubbing or effing up the stock diameter ratio too much?? The car is at stock ride height and I have no plans on lowering it. Thanks!!!

I believe 265 is the widest you can go on the stock 20’s.

 

[luc]

There is a difference between what could fit and the right tire size for a given wheel width
On a 9 inch rim that would be 255
265 max

 

[kz]

275s fit easily on 9" wide wheels, 285s will fit too but it's work and tire shop will hate you (and there is no reason for that).

255/35R20 and is exact same diameter as 255/40R19. 265/40R19 is 0.3" larger - will make gearing slightly taller in the rear.

None of these are anywhere close to rubbing anything.

 

[luc]

275s fit easily on 9" wide wheels, 285s will fit too but it's work and tire shop will hate you (and there is no reason for that).

255/35R20 and is exact same diameter as 255/40R19. 265/40R19 is 0.3" larger - will make gearing slightly taller in the rear.

None of these are anywhere close to rubbing anything.

As I said earlier, there is a difference between what will fit and what is optimum handling wise
285 on 9” will have bulging side walls and soft/imprecise turn in

 

[Bikeman315]

As I said earlier, there is a difference between what will fit and what is optimum handling wise
285 on 9” will have bulging side walls and soft/imprecise turn in

Go by the manufacturers recommendation. On a Michelin PS4S the optimum size would be a 255. A 265/275 would be on the max size but certainly useable. Anything bigger will just compromise handling.

 

[Tr33s]

Go by the manufacturers recommendation. On a Michelin PS4S the optimum size would be a 255. A 265/275 would be on the max size but certainly useable. Anything bigger will just compromise handling.

So I can go with a 275/35/20 or would it be a 275/40/20?

 

[kz]

As I said earlier, there is a difference between what will fit and what is optimum handling wise
285 on 9” will have bulging side walls and soft/imprecise turn in

Nowhere I said it would not. But vast majority of people installing 20" wheels absolutely could care less about it. I'd also risk saying that 98% of forum members agonizing over tire choice / size can't tell a turn in difference between regular and pinched fit because no one ever turns in hard enough on the street and no one should.

Fact is they will fit and if someone wants widest possible tire, it's possible.

 

[kz]

So I can go with a 275/35/20 or would it be a 275/40/20?

Spend some time understanding sized, it'll help you a lot - if you want to keep the same diameter, 275/35R20 is what you need. This will keep speedo accurate and gearing unchanged. On line tire size calculators will tell you everything you need to know.

 

[Bikeman315]

Well here are the actual numbers. Based on this 265/35-20 would be optimum. No big deal if you go to 275 like @kz said.

https://tiresize.com/comparison/

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