The 21 inch Problem - What Size to Use?

[LarryD]

Ok, so I have used up my factory originals and my spare set of Pirelli's on take off wheels and now stuck with 8 factory wheels in 21 inch and no affordable tires to put on them for my 2010 2SS... So, I have been reading about potential wheel size changes but haven't been able to decipher replacement tires and 20 inch wheels that would be a direct (or near direct) replacement for the 21's.... That is my speedometer won't be off and the handling is close to the same... I only drive it in reasonably good weather, some times in rain and never in ice or snow.. I don't do track runs so this tends to be an occasional driver in the summer time...

Did all the discussions finally settle on a tire size in 20 inch wheels to use that will get me there? If so, what route should I go???...

Thanks...

[Vegas Bound]

Search for the wheel size and tire sticky post. More info than you need. I think Pro Stock John started it.

[Deputy347k9]

Originally Posted by LarryD

Ok, so I have used up my factory originals and my spare set of Pirelli's on take off wheels and now stuck with 8 factory wheels in 21 inch and no affordable tires to put on them for my 2010 2SS... So, I have been reading about potential wheel size changes but haven't been able to decipher replacement tires and 20 inch wheels that would be a direct (or near direct) replacement for the 21's.... That is my speedometer won't be off and the handling is close to the same... I only drive it in reasonably good weather, some times in rain and never in ice or snow.. I don't do track runs so this tends to be an occasional driver in the summer time...

Did all the discussions finally settle on a tire size in 20 inch wheels to use that will get me there? If so, what route should I go???...

Thanks...

I have probably owned as many set of Camaro wheels/tires as any other member here. At this moment I just dropped to five sets on hand, just sold my last of the 21" OEM wheels and tires. I had both sets staggered and square setup. All remaining wheel sets I have are 20", two sets are SQUARE setup and three sets of staggered.

My self I like the square setup as I can rotate the tires in order to get more mileage out of them. I have had all my wheels powder coated gloss black. I have the following;

1. 2019 OEM wheels (20"X8.5") with 25MM off set, square setup wrapped with Goodyear Eagle 99Y F1 run flat tires, size 245/40/30.

2. ZL1 replica wheels (20"X10" with 35MM off set, square setup wrapped with Continental Extreme Contact DWS06 tires, size 275/35/20. Without question this is my favorite set of tires!

3. 2015 OEM SS wheels (front 20"X8.0" rear are 20"X9.0") 35MM off set for the front and 40MM for the rear. This set is also wrapped with the Continental Extreme Contact DWS06 tires, front size 245/45/20 and the rear 275/40/30

4/5 Two sets of 2015 OEM SS wheels that was just powder coated gloss black, no tires mounted on them as of yet. Both sets were extremely mint before I sent them to the powder coater, love the powder coated gloss black look. Both of these sets are staggered

My favorites are sets 1 and 2, my favorite tires are the Continental Extreme. These tires are not cheap by no means but I get great mileage with them.

[LarryD]

Thanks for the info but my head still spins with all the different sizes. As I mentioned, I am just looking for something close as possible to avoid other changes other than maybe having to compensate a little for the speedometer. I like the design of the original factory wheels (chrome and black spokes) and am a stock design guy. So I can search for wheels but need to know what size wheels and tires front and back is the question. Thought maybe there would be a quick recommendation to get close to the factory look and feel with a quick swap.

[LarryD]

I should add that I have Brembo brakes and the front ones have the counter weights (vibration dampening weights) on the back of the pads.

[JimE]

Sticky at the top of this section: https://www.camaro5.com/forums/showthread.php?t=62838

Having said that, go or call a reputable tire/wheel shop. They will be able to tell you what wheels fit (there is more to it than just picking a 20" size wheel) and then what tires fit those wheels.

Need4speed_motorsports (Paul A.) sold me my set of "winter" wheels and was a pleasure to deal with, even when answering my questions.

[LarryD]

So, I have looked at that sticky multiple times but still unclear what to buy. Given that, let me ask the question another way. Can I simply replace oem stock 21's (245/40-21 on 8.5 inch wheels front, 275/35-21 on 9.5 inch wheels rear) with the oem stock listing of 20's (245/45-20 on 8 inch wheels front, 275/40-20 on 9 inch wheels rear) ending up with a simple swap and essentially the same or very similar performance? The tire heights appear the same so no impact to speedo reading?

[JimE]

Yes. Wheel size doesn't matter for the speedo, only the tire diameter.

Handling could likely get better, assuming a quality wheel and similar or better rubber compound, as you could have less rotating mass.

[Sir Nuke]

Originally Posted by LarryD

Thanks for the info but my head still spins with all the different sizes. As I mentioned, I am just looking for something close as possible to avoid other changes other than maybe having to compensate a little for the speedometer. I like the design of the original factory wheels (chrome and black spokes) and am a stock design guy. So I can search for wheels but need to know what size wheels and tires front and back is the question. Thought maybe there would be a quick recommendation to get close to the factory look and feel with a quick swap.

Larry....ALL THREE wheel/tire combo's that Deputy posted above in post #3 will work as they are STOCK sizes and will keep you speedo CORRECT with no other changes.