What offset will work

[5150medic]

2025 Mustang GT with Brembo brakes. I currently have the 19 X 9. 5 front wheels and 19 X 10 in the rear. I am wanting to go with the square setup with 20 X 10.5 front and rear. 285/35 R20 tires. Any know what the offset for the 10.5 wheels should be front and rear? Thanks in advance.

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[needforspeedirl]

2025 Mustang GT with Brembo brakes. I currently have the 19 X 9. 5 front wheels and 19 X 10 in the rear. I am wanting to go with the square setup with 20 X 10.5 front and rear. 285/35 R20 tires. Any know what the offset for the 10.5 wheels should be front and rear? Thanks in advance.

Are you trying to get them to sit flush with the fenders or sit like they do from the factory?

 

[needforspeedirl]

2025 Mustang GT with Brembo brakes. I currently have the 19 X 9. 5 front wheels and 19 X 10 in the rear. I am wanting to go with the square setup with 20 X 10.5 front and rear. 285/35 R20 tires. Any know what the offset for the 10.5 wheels should be front and rear? Thanks in advance.

If you want them to sit a little more flush you should do:
Front 20/10.5 +25
Rear 20/10.5 +45

 

[2026DHCARB]

If you want them to sit a little more flush you should do:
Front 20/10.5 +25
Rear 20/10.5 +45

I’m no expert, but that would leave you more than an inch away from the OEM offset on the rears, that’s a poke setup. I added only 20 mm on the rears and was too much for my taste. The fronts is 13 mm, that’s what I would love to achieve.

 

[Skye]

One of our sponsors, Dragracingwheels.com, created the attached; it might help in making offset decisions.

 

[robvas]

I’m no expert, but that would leave you more than an inch away from the OEM offset on the rears, that’s a poke setup. I added only 20 mm on the rears and was too much for my taste. The fronts is 13 mm, that’s what I would love to achieve.

Have to re-calc the offsets when you change wheel width

 

[MidwayJ]

2025 Mustang GT with Brembo brakes. I currently have the 19 X 9. 5 front wheels and 19 X 10 in the rear. I am wanting to go with the square setup with 20 X 10.5 front and rear. 285/35 R20 tires. Any know what the offset for the 10.5 wheels should be front and rear? Thanks in advance.

Why do you want 10.5 wheel width if you're going with 285 tires? If you get 20x10 with an offset of 35-37 or so on all 4 you can rotate the tires front to back.

 

[needforspeedirl]

I’m no expert, but that would leave you more than an inch away from the OEM offset on the rears, that’s a poke setup. I added only 20 mm on the rears and was too much for my taste. The fronts is 13 mm, that’s what I would love to achieve.

Yeah that’s not correct. The wheel width is used in the calculation. 10.5 is wider than 9.5.

 

[2026DHCARB]

Have to re-calc the offsets when you change wheel width

Yes I did.

 

[MidwayJ]

I’m no expert, but that would leave you more than an inch away from the OEM offset on the rears, that’s a poke setup. I added only 20 mm on the rears and was too much for my taste. The fronts is 13 mm, that’s what I would love to achieve.

Here's the change from OEM. It's not more than an inch. It's a 20mm difference which is ideal.

 

[2026DHCARB]

Fronts:
9.5/40 to 10.5/25 -> 28 mm

Rears:
10.0/52.5 to 10.5/45 -> 13 mm

that’s my calculation

 

[MidwayJ]

Rears:
10.0/52.5 to 10.5/45 -> 13 mm

that’s my calculation

I agree with that. But you said it would push the rear out more than an inch and "poke." 13 mm won't poke.

(In what I posted before I used OEM PP wheel size of 9.5. Apparently the OP has the base Dark Horse wheels 10 inches wide on his GT.)

 

[MidwayJ]

Rears:
10.0/52.5 to 10.5/45 -> 13 mm

that’s my calculation

I agree with that. But you said it would push the rear out more than an inch and "poke." 13 mm won't poke.

(In what I posted before I used OEM PP wheel size of 9.5. Apparently the OP has the base Dark Horse wheels 10 inches wide on his GT.)

 

[2026DHCARB]

I meant front, sorry. 28 mm on the fronts I believe is too much vs OEM DH w/o HP.

 

[needforspeedirl]

Yes I did.

Here is 19x11 +52

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