21 tires question!!!

[14M6GCoupe]

I have 265/30/21 i was wondering if i can put 275/30/21? Does any boy have try this or knw about this! Help pls i have to buy a set i dnt want to buy the wrong tires! Thankz! 2014 bmw m6 gc

[14M6GCoupe]

Anybody???

[mastatikle]

They’ll both fit up front. It just depends on your rear tire size.

[14M6GCoupe]

Originally Posted by mastatikle

They’ll both fit up front. It just depends on your rear tire size.

I was thinking 325 30 21

[98mkiv]

so just do the math. You want your tire diameter to remain constant.

WWW/RR-DD

Use the formula (DD*25.4)+(2*(WWW*(RR/100)) = Outer diameter of tire

Apply that to your stock tire size.

Your new tire size should be adjusted so that the D/R/W comes out to the same number. That way your speedo stays accurate and your suspension geometry also works the way it was designed to. Keep in mind this does not account for width, meaning you might rub on the fenders or suspension parts over bumps or during turns.

Hope that that helps.

If you have a question - put up your factory tire sizes and your proposed sizes.

[mastatikle]

Originally Posted by 14M6GCoupe

I was thinking 325 30 21

Front and rear tire have to me close to the same diameter or else the car won’t run right. Ask me how I know... I have 325/30/21 in the rear and 275/35/21 in the front and it rubs a good amount. But the car also drives normally. I plan to downsize to 255/35/21 to bring diameter down a bit so it doesn’t rub. 275/30/21 might be too small. I had 255/30/21 in front and it fit but since rear tire diameter was like 2” taller the car wouldn’t shift right.

[14M6GCoupe]

Originally Posted by mastatikle

Front and rear tire have to me close to the same diameter or else the car won’t run right. Ask me how I know... I have 325/30/21 in the rear and 275/35/21 in the front and it rubs a good amount. But the car also drives normally. I plan to downsize to 255/35/21 to bring diameter down a bit so it doesn’t rub. 275/30/21 might be too small. I had 255/30/21 in front and it fit but since rear tire diameter was like 2” taller the car wouldn’t shift right.

Ohh okai i see what u saying

[14M6GCoupe]

Originally Posted by 98mkiv

so just do the math. You want your tire diameter to remain constant.

WWW/RR-DD

Use the formula (DD*25.4)+(2*(WWW*(RR/100)) = Outer diameter of tire

Apply that to your stock tire size.

Your new tire size should be adjusted so that the D/R/W comes out to the same number. That way your speedo stays accurate and your suspension geometry also works the way it was designed to. Keep in mind this does not account for width, meaning you might rub on the fenders or suspension parts over bumps or during turns.

Hope that that helps.

If you have a question - put up your factory tire sizes and your proposed sizes.

Lol big equation my friend ill figured it out some how thank u for the help!

[14M6GCoupe]

Have anybody try out 325 30 21 on the rear and 267/275 3 21 on the front? Does that is a good match? Help pls

[mastatikle]

Originally Posted by 14M6GCoupe

Have anybody try out 325 30 21 on the rear and 267/275 3 21 on the front? Does that is a good match? Help pls

What for front?

[14M6GCoupe]

Originally Posted by mastatikle

What for front?

265 30 21 or 275 30 21