NVR2L8

I have been experimenting with different tire brands and compounds for the last few years.

With a shop full of partial sets of tires, a few months ago I asked about mixing R-Comps (Hoosier, GY, etc.), and most agreed that it was OK for HPDE events.

Still looking to use up my odd ball tire supply, I have two 345-19 Michelin Pilot Sport Cups (TW 80, 50% tread), and several 275-18 Nitto NT-01 (TW 100, 75% tread).

I know the hardcore racers probably wouldn't touch this combo, but how about the casual drivers like me? I have a few thousand dollars in tires and would like to use them up. Thoughts?

BTW, I have chosen the Michelin Pilot Super Sports as my permanent track tire for the future, so I don't want to buy any more R-Comps, Sport Cups or Nittos.

TIA.

crimlwC6

Car worth vs running used tires, that is the equation. If you are asking the internet for advice you probably know the answer. I run nt01s in race group for 2 or 3 three weekends but i know my driving and my car and toss after 6 months regardless of heat cycles. Tires have a shelf life so the easy answer is buy fresh and run them out.

VetteDrmr

You are honestly your best source for what to do. Yes, if you mix tire brands, compounds, age, etc. you won't get optimum results. No, the car won't explode, meteorites won't fall on you, etc. Old tires get hard, lose grip, etc., so you just have to manage.

Are you willing to give a point by so you can drive to the limits of your tires, which are now worse than they used to be? If so, then go out and have fun. If you want the best performance you can get out of your car, then sell them cheap to someone just getting off their first track day that doesn't want to tear up their street tires. Then you can move forward without the garage inventory.

HTH, and have a good one,
Mike

hungryhippo

Sure you can, but are you willing to waste track days just so you can use up some tires?

Rexracer77

Maybe Im just poor, or rather don't have the excess funds to throw at playing like other people, and maybe knowing that I know I am not out to go 10/10th all the time and be pushing the limits at every second.

Last track day, I ran R888s in the back (100) and old rock hard Falkens (500). Car was surprisingly balanced and easy to drive (not enough front traction to make the it tail happy, but still not pushing).

Did I set any lap records? Nope, but that was never my plan, I had a very enjoyable day at the track, doing some laps, blowing by some lotus's and M3s.

So no, your car wont blow up, accept it for what it is and enjoy it.

Or ship them out to me, ill use them up for you. ;-)

argonaut

Take what they give you, adjust as necessary, be smart and have fun! No big deal.

Bill Dearborn

If you are using up old tires you can mix brands/compounds without worry as long as the tire with the most grip is in the rear. I have run road race slicks/R compounds in the rear with Michelin PS street tires in front. The car understeered a lot but that was workable. Reversing the combination would have made it very tricky to drive.

Bill

NVR2L8

Thanks guys for the input.

This place can be a pretty tough crowd sometimes, and I thought for sure that I would be nailed pretty hard for even considering mixing tires.

I am definitely a couple rungs down the ladder from the serious driver, most of my events are just for fun.

Thanks for the support!

ratt_finkel

I wouldn't hesitate to run mismatched tires on the track or autocross course.

For a corvette. I would prefer to have the sticker compound tire on the rear. And assuming there is a not a huge variance in grip, the one that is more heat tolerant in the front.

I would caution against making any permanent set up changes based on those tires though. Would definitely play with air pressure, shock settings and possible sway bar settings if I really wanted. But just to balance the car. Not purely to go after faster times.

For an autocross, I'd prefer the better tires on the front. As rotation is a desirable trait in that venue. Same rules apply.

I never advocate mixing street tires with Rcomps and vice versa. The characteristics are so far apart that it's not even worthwhile.

C6psi

I did a track day last weekend with Hoosier R6's on the rear with about 20 heat cycles and fairly new MPSC's on the front. I was traction limited up front, as I expected, and pushed in the corners pretty bad. As the day went on I beleive the R6's began to heat cycle out and got pretty greasy as I could lay black stripes coming out of some of the turns for about 60 feet. I have come to the conclusion that I am not very good at dialing it back to 7/10ths to compensate for running out differing tire compounds so I will stick with like compounds at all 4 corners!

TorontoC6

You can run mixed compounds but it's more challenging and you will have to keep a little bit of 'reserve' (i.e. not run at 10/10 th's). One of the key challenges that was not mentioned is that the car's balance can change as you warm the tires up. Different compounds will heat up at different rates and have different levels of grip. That means that the the car's balance between oversteer and understeer can change depending upon which lap you are on.

Supercharged111

If you ran a square setup, you could throw the stickier tires on the outside.

Beatnik

If you are running mixed compounds on track and it is working, you either aren't pushing the car OR it's really unbalanced, which a late model Corvette takes some talent.

VetteDrmr

Running at 10/10s is only smart during competition; autocross, TT, or W2W. Keeping some in reserve at a DE is only smart, even if you're running in the instructor group.

Biggus Blockus

I've been mixing tires front and back for years. Currently I have 315 Hoosier A6s on the front and 315 Kumho 710s on the rear.

I agree that stickier tires go on the rear for high speed AutoX / road racing / HPDEs but have found that for low speed Auto X the stickier set goes to the FRONT on the car for better times. At least with my C4 that understeers naturally. YMMV.

As long as you are educated about your car, the tires, and your total setup you can mix and match rubber. I had a few people stop at my spot in the pits watching me move tires around after a low speed Auto x on Sat in anticipation of the High speed AutoX on Sunday, wondering why I was "rotating my tires" :-)