[Corbu]

OK, so I am done done with the Goodyear Eagle F1 run-flats on this car (been through 4 sets already) and I want to get a non run-flat tire that is quieter on the road but mainly with a bit more bite on the track. I am running the track wheel alignment year round. In stock form and with the stock Goodyear Eagle F1 tires the car understeers like crazy on the track, it doesn't have enough grip on the front. My goal with the new tire setup is to reduce the understeer and also have a bit more overall grip than what I currently have with the Eagle F1 ... The Indy 500 seems like a good upgrade that also doesn't break the bank.

I am a bit stuck and I don't know what is the best size tire moving forward: either all stock or wider tires.

The size options available for the Indy 500 tire are:

245/40/R20 (front stock), 255/35/R20 on 8.5" wide factory rim
275/35/R20 (rear stock), 285/35/R20, 285/30/R20 on 9.5" wide factory rim

How should I best mix and match the tires so that it actually feels better on the track and the road?

Next year I plan on getting 18" or 19" wheels for the track only and I'll have better tires available then, but for now, I need to stick with something that will fit on the factory SS 20" wheels and be good on the road and also on the occasional track day. My car has Mag-Ride in case it matters.

Thank you.

[enzia35]

I'd get stock sizes. Chevy actually did a good job following the rule of having the tread width be up to 1/2in narrower than the wheel width.

https://motoiq.com/how-to-properly-s...r-performance/

[WhiteMale]

Id stay stock that 10mm of width isn't giving you much of anything at all. Good tires though great for hard street use but there's better out there in that category albeit at a higher price point. I had them on my Mustang GT/PP1 car.

[Msquared]

I agree with sticking with stock sizes. However, I would suggest two better do-it-all tires for your consideration:

• Michelin Pilot Sport 4S
• Continental ExtremeContact Sport

Both of these are fantastic dry-weather tires and will hold up for track use. They are also the two best street-legal rain tires that you can get (even better than any all-season). They are easily good to below freezing temps, too. I consider them more of a "three season" tire.

[Corbu]

These are about $1000 more in Canada compared to the Indy 500, almost 3/4 more than a set of Indy 500. The Michelin Pilot Sport 4S would have been my top choice, but it too expensive, I'd rather get almost 2 sets of Indys and have rubber to spare for the track.
I also have a set of winter tires, so this set will be used in the summer only.

If I keep the stock 275/35R20 for the rear but go a tad more than stock on the front with 255/35/R20 rather than 245/40R20, would I gain a bit more front end grip on the track? I was not happy at all with the understeer I had with he Goodyear F1 in stock size; the back end I could manage with the throttle, but the weak front does not inspire confidence...

[WhiteMale]

I run the ECS and I don't recommend them, sidewall feels squishy and vague turn-in like it has to roll over before it bites, my 1LE feels like it has a hard push on the front end. Wear nice, ride nice, rain friendly, but you push it hard and it gives up really easy. I'm about to put them back on my car when I swap my winters off and I'm going to try a different alignment shop and see if that makes anything better.

[TP2SS]

Originally Posted by Msquared

I agree with sticking with stock sizes. However, I would suggest two better do-it-all tires for your consideration:

• Michelin Pilot Sport 4S
• Continental ExtremeContact Sport

Both of these are fantastic dry-weather tires and will hold up for track use. They are also the two best street-legal rain tires that you can get (even better than any all-season). They are easily good to below freezing temps, too. I consider them more of a "three season" tire.

Interesting! I've been considering PS4 AS's to replace my OEM F1 A3 RoF's. I looked at the PS4S's too, but they rate about the same as the OEM GY's as far as wet traction (on tirerack), so it got me thinking why would I change? Nowhere on the Michelin website does it say what temps "summer" tires are good down to, so I'm wondering where you see they are good below freezing. My car will never see snow, but I would like to have the ability to drive near/below 40 if I want/need to, as well as not worry about rain. The tread patterns on the OEM GY's and the PS4S's look an awful lot alike too. I like the "3-season" idea. So far the car has never been driven in rain, but I anticipate doing some road trips and it's gonna see the wet stuff eventually. I do want to keep the ability to drive "spirited" too, but will never track the car.

[arpad_m]

Originally Posted by TP2SS

Interesting! I've been considering PS4 AS's to replace my OEM F1 A3 RoF's. I looked at the PS4S's too, but they rate about the same as the OEM GY's as far as wet traction (on tirerack), so it got me thinking why would I change? Nowhere on the Michelin website does it say what temps "summer" tires are good down to, so I'm wondering where you see they are good below freezing. My car will never see snow, but I would like to have the ability to drive near/below 40 if I want/need to, as well as not worry about rain. The tread patterns on the OEM GY's and the PS4S's look an awful lot alike too. I like the "3-season" idea. So far the car has never been driven in rain, but I anticipate doing some road trips and it's gonna see the wet stuff eventually. I do want to keep the ability to drive "spirited" too, but will never track the car.

If you mean the OEM Eagle F1 Asymmetric 3 runflat tires that the non-1LE SS comes with, there is absolutely no comparison between those and the PS4S. The Goodyears are useless in a downpour, heck, you'll see the rear wiggle all over the place even on slightly wet surfaces at 30-40% throttle if the temperatures aren't ideal.

Their TireRack wet traction ratings are vastly different, too: 5.8 vs 9.1, not even in the same ballpark, which my personal experience confirms to one hundred percent. Wet traction with the PS4S is unreal, at the stock SS power level the wet and puddly road surface drove almost exactly the same as dry, with the wipers on full duty.

[BDPhoto519]

I run the 500's in the 285 on the oem 9.5 rim for daily driving. It fits like it should and was in stock compared to the 275 at the time.

[Corbu]

What do you have on the front 8.5" rim ?

[TP2SS]

Originally Posted by arpad_m

If you mean the OEM Eagle F1 Asymmetric 3 runflat tires that the non-1LE SS comes with, there is absolutely no comparison between those and the PS4S. The Goodyears are useless in a downpour, heck, you'll see the rear wiggle all over the place even on slightly wet surfaces at 30-40% throttle if the temperatures aren't ideal.

Their TireRack wet traction ratings are vastly different, too: 5.8 vs 9.1, not even in the same ballpark, which my personal experience confirms to one hundred percent. Wet traction with the PS4S is unreal, at the stock SS power level the wet and puddly road surface drove almost exactly the same as dry, with the wipers on full duty.

I stand corrected! I clicked on the link that showed AVERAGE ratings for all tires in the category and didn’t notice that it wasn’t for the GYs alone! When I just clicked the ratings within each tire’s link it showed your 5.8 vs 9.1! Thanks for setting me straight! So I guess the only thing I need to know, is the PS4S truly a 3-season tire I can safely drive down to 32 as long as there’s no snow?

[arpad_m]

Originally Posted by TP2SS

I stand corrected! I clicked on the link that showed AVERAGE ratings for all tires in the category and didn’t notice that it wasn’t for the GYs alone! When I just clicked the ratings within each tire’s link it showed your 5.8 vs 9.1! Thanks for setting me straight! So I guess the only thing I need to know, is the PS4S truly a 3-season tire I can safely drive down to 32 as long as there’s no snow?

I have only driven them in 37-38 degree weather, they were fine, with delicate throttle control of course. 32 may be pushing it, though, this is a max performance summer tire after all...

[Msquared]

Originally Posted by TP2SS

Interesting! I've been considering PS4 AS's to replace my OEM F1 A3 RoF's. I looked at the PS4S's too, but they rate about the same as the OEM GY's as far as wet traction (on tirerack), so it got me thinking why would I change? Nowhere on the Michelin website does it say what temps "summer" tires are good down to, so I'm wondering where you see they are good below freezing. My car will never see snow, but I would like to have the ability to drive near/below 40 if I want/need to, as well as not worry about rain. The tread patterns on the OEM GY's and the PS4S's look an awful lot alike too. I like the "3-season" idea. So far the car has never been driven in rain, but I anticipate doing some road trips and it's gonna see the wet stuff eventually. I do want to keep the ability to drive "spirited" too, but will never track the car.

I have the PS4S on my car as street and rain competition tires. I ran through my set of OE Goodyears, and still plan to use those tires on dry/warm track days. I autocross now on Falken RT660s. And I have a shitty set of all-seasons for "winter" use (they are equally shitty in all seasons). So that's my personal comparison subject pool.

A few weekends ago I did a track day in Joliet, IL. Because of the forecast, I left the PS4S s on the car. The first half of the day was dry but in the high 30s (F). They did quite well, gripping well after literally just a few turns, whereas guys on Goodyears took 2-3 laps to get enough heat to work at all. some on Falkens seemed closer to my Michelins in warmup time: those tires are pretty good without any heat in them. The Falkens definitely had more grip than the PS4Ss in the dry, but the Michelins were consistent and easy to manage. Their biggest shortcoming was in putting down power out of corners - the Falkens are champs at that.

Then it rained and the temps "climbed" to about 42F. We had puddles on track at times. The guys with Goodyears were nowhere, no matter how many laps they spent trying to build heat. Falkens were tolerable when the surface was wet but without standing water, but they have a relatively fast breakaway and it was clear they were not getting "switched on" fully. IME they are okay on a damp surface but don't like lots of water, and on that day the rain would keep starting up again so that the puddles never completely went away. OTOH, I just kept going out in the rain and pounded in lap after lap. There were some spots where hydroplaning was inevitable, especially on one straight where the puddles collected right in the braking zone. But recovery was always fast and easy to manage. Elsewhere, the tires worked well, especially on lateral grip. They made it pretty easy to look like a hero.

Then, to get ready for the 5-hour drive home that evening, I did...absolutely nothing. That was pretty nice!

[TP2SS]

MM,

That's great info, thanks! I think I'll go with the PS4S's now. Don't ever "plan" to drive the car below 40, but if I "have" to, I'll be covered.
Too bad you're too far away, I'd sell you my OEM GY's to use on the track for a good price!