I have these used tires for my ap1 laying around in my garage and I have snow tires on my car. The tires in the garage are ultra high performance all season tires(according to tirerack) but the tread is at 4/32 in the back and 6/32 in the front. My question is how will the treadwear affect grip for autocross/track events? Im thinking of using them this summer and im planning on attending some autox and im wondering if I should save up for new tires or just use these up.

 

buy new ones, no need to spend money to mount junk tires. Ill put it this way, i went on a road trip one weekend and was planning on buying tires the afternoon before i left, but had to work late and didnt have time. That bad judgement cause me to end up in a guardrail going around a turn and i was only going about 20. Im now a firm believer that the s2k does not like half bald tires. I will never have tires on my car again that are questionable.

 

Yea I wanna do that but I dont have a lot of money or a job at the moment and it would take a while before I could buy them, so I would have to be on my snow tires in the spring and summer for a while.

 

Try looking at racing tires.

But keep in mind that if you're low on cash then you definitely can't afford to mess around in the rain on balding tires.

Either way, save up.

 

If you're low on money, definitely don't track or autox the car. Things can break and then your reliable transportation isn't so reliable anymore.

That being said, get another set of tires. An investment in a decent set of all seasons that could last you a while might be what you need right now. Since you're just starting out, you'll be ok to track and autox on them as well when the money comes.

 

$50 to mount and balance free tires is cheaper than buying new. 4/32" is not a lot, but if you are not driving in the rain, run 'em bald.

 

I am going to be a bit radical here.

Tires have treads for three reasons.
1/ It vastly improves grip on a wet road by providing water clearance channels.
2/ A tread makes the tire more flexible, and reduces heat buildup at sustained high speeds/loads.
3/ Tread usefully indicates tire wear.

Another observation:
The rubber provides grip, the spaces between do not, which is why slick tires are used for serious racing on smooth dry grippy surfaces.

The only thing wrong with almost worn out tires is that they can kill you in the wet.
On a bright sunny day on a smooth surface they will be fine.

Look at some of the serious "R" rated ultra soft compound semi racing slicks, and tell me they must be deadly dangerous because they have almost no tread.

 

You are completely fine and wont crash your car because you put these tires on. I run all of my tires until they cord (live in california so I dont have to deal with anything besides a little rain). The big concern with tread depth is hydroplaining resistance... thats it. But they're all seasons so they are heavily grooved and siped meaning they can evacuate more water. The legal limit on road tires is at the wear bars or 2/32 of an inch which is still pretty conservative, just don't do 80mph down the freeway when its raining. People claim wet traction goes to sh*t when the tires get that low but the tread depth has nothing to do with it, it's the fact that by the time the tires get to be that worn they have been through many heat cycles that harden the compound up.
In the dry your all seasons will feel like garbage compared to a UHP summer or extreme performance summer tire (star spec, nt-05, R-S3...) which should be your next category of tires if you get more serious about autox or catch the track bug. If you're low on cash you mught want to hold off on autocross because you will burn through tires, brakes, and possibly break something. However, if you do want to try it then you'll be fine on you;re tires. Contrary to what the guy above me says, having less tread is better for the dry because it reduced heat build up. Ever wonder why most dot legal r-compounds come with 6/32 (nt-01, r888) and full blown slickish racing tires come with 4/32 (r6,a6,v710,c51,c71,r1)? Also people that are very serious will but tires and shave them to 2 or 3/32 because less tread means less tread squirm and heat buildup which translates into a faster more responsive tire. The bottom line is you should put them on but dont speed down the freeway when they wear down a little more. Go to a big parking lot and slide your car, find the limits and feel how it reacts. My guess is you'll be surprised how much drip your car has with these "questionable" tires have.

 

Thanks for the information. This is exactly what I wanted to know.

 

I agree to a point, I thought some tires start loosing their grip as they wear down beyond the wear bars, I thought the compound was not the same. I know for my previous two tires, RT615's and Continental procontact 2's, they did not grip as well with zero tread, than with full or some tread. I started spinning out at autocrosses a lot easier with bald tires (non R compound). R compounds are different tho, you can wear those to the wires and still be super grippy. you guys are comparing R compounds to all seasons? come on. tread wear of 400 to 100? harder tires are not going to be as safe as softer tires in dry conditions, the tread on harder tires is whats giving you grip. you don't see ppl shaving all seasons to 3/32nds. It all depends on the material the tires are made of. The guy has all season tires, not summer and definitely not R compounds lol, don't give the guy specs for R compounds and tell him he will be fine on his all seasons.