[Could've_had_a_V8]

Is there any reason to put 275s in the rear of the V6? I want new tires for street and track and I don't know if I should stick with the square 245s or go staggered. I figure that the extra grip from the 275s in the rear won't outweigh the understeer it causes because the V6 doesn't have much hp or torque. But I wanted to get some opinions from the experts on this forum. Thanks in advance!

[Thelma - 2017 RS]

following. I also am contemplating the change over to 275's in the rear.

[Provoste]

SS 1LE doesn’t NEED to be staggered.... V6 definitely doesn’t. 275-285 square on a 9-10 inch wheel would be ideal. Apex has what you’re looking for.

[Could've_had_a_V8]

Originally Posted by Provoste

SS 1LE doesn’t NEED to be staggered.... V6 definitely doesn’t. 275-285 square on a 9-10 inch wheel would be ideal. Apex has what you’re looking for.

I can fit 275s in the front? Who is Apex? Thanks!

[Provoste]

Originally Posted by Could've_had_a_V8

I can fit 275s in the front? Who is Apex? Thanks!

Yes, 275 will fit up front. Apex wheels, they fit our cars. These would likely work square, but I’d confirm with Apex first. Ryan is their Camaro specialist.
https://www.apexraceparts.com/shop-b...c-8-wheel.html

I have 2 sets of Apex wheels, 305’s can fit up front easy on the right wheels.

[Could've_had_a_V8]

Originally Posted by Provoste

Yes, 275 will fit up front. Apex wheels, they fit our cars. These would likely work square, but I’d confirm with Apex first. Ryan is their Camaro specialist.
https://www.apexraceparts.com/shop-b...c-8-wheel.html

I have 2 sets of Apex wheels, 305’s can fit up front easy on the right wheels.

I wasn't planning on changing the wheels. But thanks again!

[Roostie]

If you're going to stick with your OEM wheels that are the same width front and rear, don't get staggered tires. When you squeeze a 275 tire on a rim better suited to a 245 width tire, you get reduced benefits. Also, increasing tire width for the rear axle will balance that car's handling towards understeer, which is not helpful and is less fun on the track. Looks good on the street, though. Instead, when you wear out the 245s, just replace them with a set of "ultra high performance summer tires." You can drive summer tires all year long in San Jose; it is a myth that summer tires perform poorly in the rain, most summer tires will outperform all-season tires in the rain.

I don't know if you have 18" wheels or 20". In a 245/40/20, something like a Firestone Firehawk Indy 500 is a high-performing, economical choice. If you have 18" wheels, there isn't a good selection of summer performance tires in the 245/50/18 size, and may need to get an Ultra High Performance All-Season tire like the Pirelli P Zero All Season Plus if you want to stay at a reasonable price-point.

[Could've_had_a_V8]

Originally Posted by Roostie

If you're going to stick with your OEM wheels that are the same width front and rear, don't get staggered tires. When you squeeze a 275 tire on a rim better suited to a 245 width tire, you get reduced benefits. Also, increasing tire width for the rear axle will balance that car's handling towards understeer, which is not helpful and is less fun on the track. Looks good on the street, though. Instead, when you wear out the 245s, just replace them with a set of "ultra high performance summer tires." You can drive summer tires all year long in San Jose; it is a myth that summer tires perform poorly in the rain, most summer tires will outperform all-season tires in the rain.

I don't know if you have 18" wheels or 20". In a 245/40/20, something like a Firestone Firehawk Indy 500 is a high-performing, economical choice. If you have 18" wheels, there isn't a good selection of summer performance tires in the 245/50/18 size, and may need to get an Ultra High Performance All-Season tire like the Pirelli P Zero All Season Plus if you want to stay at a reasonable price-point.

Thanks very much for all the info. I have the 20" wheels and was, in fact, considering the Firestones. However, I'm wondering whether the Continental Extreme Contact Sport is worth the extra money. But that's a topic for another thread. Thanks again!

[Snrub]

Agree about the use of summer tires, however not all summer tires are created equal. Tire Rack uses the parlance of "Max Performance" for a category which seem to have better wet performance than the "Ultra High Performance" tires. If you take a look at Tire Rack's testing data something like the Firestone Indy 500, it does a dry/wet lap time of 30.02/35.45. The Conti ECS does 30.40/33.28. While you cannot compare directly between tests (ignore the absolute times), notice the amount of difference between the dry/wet performance. Also note that GRM had very different wet results between the Michelin PS4 and the ECS, suggesting Tire Rack's test may be closer to damp than really wet. I really question the Indy 500's ability to evacuate water during a torrential down pour.

You can also tweak the sizing to optimize cost/availability rather than compromising with a no-season tire. The OEM tire size is ~27.7." You can get the 27.3" tall 235/50/18 Conti ECS, or the 27" tall 255/45/18, or 28" tall 255/40/20. Keep in mind that half of the height difference will show up in the change to the fender gap and there will be a slight change to speedometer reading and gearing (smaller will improve it). You don't need to focus too much on width. There is more or less no cornering performance advantage of going beyond a 215 wide tire on a 8.5" wide wheel.

[Could've_had_a_V8]

Originally Posted by Snrub

Agree about the use of summer tires, however not all summer tires are created equal. Tire Rack uses the parlance of "Max Performance" for a category which seem to have better wet performance than the "Ultra High Performance" tires. If you take a look at Tire Rack's testing data something like the Firestone Indy 500, it does a dry/wet lap time of 30.02/35.45. The Conti ECS does 30.40/33.28. While you cannot compare directly between tests (ignore the absolute times), notice the amount of difference between the dry/wet performance. Also note that GRM had very different wet results between the Michelin PS4 and the ECS, suggesting Tire Rack's test may be closer to damp than really wet. I really question the Indy 500's ability to evacuate water during a torrential down pour.

You can also tweak the sizing to optimize cost/availability rather than compromising with a no-season tire. The OEM tire size is ~27.7." You can get the 27.3" tall 235/50/18 Conti ECS, or the 27" tall 255/45/18, or 28" tall 255/40/20. Keep in mind that half of the height difference will show up in the change to the fender gap and there will be a slight change to speedometer reading and gearing (smaller will improve it). You don't need to focus too much on width. There is more or less no cornering performance advantage of going beyond a 215 wide tire on a 8.5" wide wheel.

Thanks for all the info. I live in California where it barely rains. Therefore, I'm not as concerned about wet performance.

[Roostie]

Also, you will push your car harder in dry conditions. Wet roads are unpredictable, so good drivers generally take it easy in the rain.

I disagree that you fail to get any benefit from wider-than 215 tire on an 8.5" rim. Shops may not even mount a 215 on an 8.5" rim because that rim is wider than the recommended fitment range for a 215. An 8.5" rim is the max width rim for most 245/50 tires. I just bought wheels and 245/50 tires, and had to get the 8.5" rims even though 9" was available, because 9" is outside the range for the 245/50 tire size I wanted.

While it is true that you will get best performance out of a tire by putting it on the widest rim within the manufacturer's fitment range for that tire, it is not true that you gain no benefit from putting more than the narrowest tire that will fit on a given rim. I have studied this issue extensively for competitive autocross.

[Roostie]

A note about the Firestone Indy 500's: I read on this forum that they are greasy and don't perform well until they're broken in with a couple hundred miles of wear. A lot of other tires feel great right from the start, but apparently these Firestones need just a little mileage before they perform their best.

[Could've_had_a_V8]

Originally Posted by Roostie

A note about the Firestone Indy 500's: I read on this forum that they are greasy and don't perform well until they're broken in with a couple hundred miles of wear. A lot of other tires feel great right from the start, but apparently these Firestones need just a little mileage before they perform their best.

Thanks for all the info. I think I've decided to go square. I don't want to change.the car's handling dynamics toward understeer. Especially since it doesn't have much power or torque.

[DirectTo]

Anybody have a square 19” setup? Curious to get some info on specs.