Rim/Tire size question

[wsmith]

I'm wondering if 20 in rims would fit on a Camaro that came with 18'ers and if you how would I know what size tires to put on them? How do you calculate that? Does it have to have the same diameter as the originals?

[KillboyPowerhead]

The same chassis is used all the way through, from base model V6 to Z/28, so any wheel that fits one trim level will fit any another (except that brake caliper clearance may be an issue with some wheels, but the V6 gets the smallest brakes so nothing to worry about here ).

What is your goal here? You can install the RS/SS wheels which are 20x8 front, +35mm offset, 245/45 tires, and 20x9 rear, +40mm offset, 275/40 tires; or you could do factory 20x9's all around; or ZL1/1LE wheels and tires; or aftermarket wheels with the same or similar overall diameter and offsets. If you want to be conservative you could go with RS/SS sizes, or if you want width then ZL1/1LE sizes works; and 275/40/20 front, +23mm offset, and 315/35/20, +43mm offset (same offsets as factory ZL1/1LE wheels) are popular; a square setup with 10" wide wheels and +35mm offset is also popular and allows you to rotate all four tires.

The overall tire diameter ranges from ~27.85" to ~28.66".

[wsmith]

Originally Posted by KillboyPowerhead

The same chassis is used all the way through, from base model V6 to Z/28, so any wheel that fits one trim level will fit any another (except that brake caliper clearance may be an issue with some wheels, but the V6 gets the smallest brakes so nothing to worry about here ).

What is your goal here? You can install the RS/SS wheels which are 20x8 front, +35mm offset, 245/45 tires, and 20x9 rear, +40mm offset, 275/40 tires; or you could do factory 20x9's all around; or ZL1/1LE wheels and tires; or aftermarket wheels with the same or similar overall diameter and offsets. If you want to be conservative you could go with RS/SS sizes, or if you want width then ZL1/1LE sizes works; and 275/40/20 front, +23mm offset, and 315/35/20, +43mm offset (same offsets as factory ZL1/1LE wheels) are popular; a square setup with 10" wide wheels and +35mm offset is also popular and allows you to rotate all four tires.

The overall tire diameter ranges from ~27.85" to ~28.66".

Wow! Thank you very much! This is exactly the type of info I'm looking for!

I think the ZL1 wheels are really cool and would love to upgrade my boring stock wheels to that. Are you saying that I can get the 275/40/20's all the way around or do I have to get the larger rear ones? And if I get the same size for all four will decrease the handling characteristics at all?

Also, what is the offset? Is that how far out or in the wheels are fastened to the axle?

And what about the lower profile tires (275/40/20) will it make the ride a little bumpier? And if so, does it require better suspension to make it ride well?

[KillboyPowerhead]

Having wider tires up front will allow for better cornering ability because of the extra meat up front, and a square/semi-square setup (same tire size all around) will reduce the inherent understeer of the Camaro, allowing for harder cornering and thus more fun. If you have 275 front and 315 rear you will still have the cornering ability of 275 all around, but with the wider rears the rear will continue to stick while with 275's on the rear they would eventually start to slide (assuming the car is more prone to oversteer than understeer). Also, wider rears allow for better acceleration by having more meat at the drive wheels. If you race you'll likely want a square setup but for the street the staggered might be preferred (although 275 all around is probably adequate for any street situation).

275/40 profile (also same as 245/45 or 315/35) will be a bit harder/bumpier but will also respond to steering inputs better due to less flex. No suspensions changes are needed to accept the lower profile (this is a stock profile from the factory).

Do a search for wheel offset, but basically it is the distance from the mounting surface of the wheel to the centre of the wheel rim, so if the mounting surface is directly in line with the centre of the inside of the rim the offset would be zero; if the mounting surface moves in toward the inside of the wheel/car (meaning the wheel would stick out farther from the car) this is a negative offset; positive is the opposite and a greater positive offset moves the wheel in, closer to the car. Offset is typically measured in millimeters.

[Avenging Orange]

Right above your post is a sticky with lots of good info

[wsmith]

Originally Posted by KillboyPowerhead

Having wider tires up front will allow for better cornering ability because of the extra meat up front, and a square/semi-square setup (same tire size all around) will reduce the inherent understeer of the Camaro, allowing for harder cornering and thus more fun. If you have 275 front and 315 rear you will still have the cornering ability of 275 all around, but with the wider rears the rear will continue to stick while with 275's on the rear they would eventually start to slide (assuming the car is more prone to oversteer than understeer). Also, wider rears allow for better acceleration by having more meat at the drive wheels. If you race you'll likely want a square setup but for the street the staggered might be preferred (although 275 all around is probably adequate for any street situation).

275/40 profile (also same as 245/45 or 315/35) will be a bit harder/bumpier but will also respond to steering inputs better due to less flex. No suspensions changes are needed to accept the lower profile (this is a stock profile from the factory).

Do a search for wheel offset, but basically it is the distance from the mounting surface of the wheel to the centre of the wheel rim, so if the mounting surface is directly in line with the centre of the inside of the rim the offset would be zero; if the mounting surface moves in toward the inside of the wheel/car (meaning the wheel would stick out farther from the car) this is a negative offset; positive is the opposite and a greater positive offset moves the wheel in, closer to the car. Offset is typically measured in millimeters.

Thanks! This rocks!