Rule Update

[66SuperSport]

Good Guys has posted that 180 treadwear tires will now be allowed in the Street Challenge Autocross events. They also state that the tires can not be shaved or treated.

[firebob]

I run GY sports car race tires at the track. Do GGs allow these? I didn't know they had tire restrictions.

Robert

[79-TA]

Technically, you can run whatever you want. It's just a matter if you want your car to be in contention for the autocross win. If your Good Years are the Eagle "F1 super car" tires, you should be fine. If they're an R compound of some sort (like like the DOT approved EAGLE RS), you're way under the UTQG treadwear limit.

[firebob]

There's no tread to speak of on these tires. They're basically very sticky slicks. I guess since they call it "street challenge" that kind of rules out race tires. Hadn't thought about that before.

Robert

[-The Stig-]

Hasn't that always been the rule? It's always been 180 right?

[79-TA]

^ It was last year at least. That's what Mary won on.

[Steve1968LS2]

Hasn't that always been the rule? It's always been 180 right?

It was 180 and they got FUBAR'd up and said "200 tread depth" which made no sense.

Then they said they meant 200 TW.. some of us argued the point since people had bought and ran 180tw tires..

It seemed silly to split hairs over 180/200 so they went back to 180..

Of course I've already gotten rid of my 180s and now run 220s.. lol.. but I'm sure some people, like Mary, are very happy they don't have to buy new tires.

[Van B]

Is there a uniform way that the manufacturers measure the treadwear rating? From what I have been told, one manufacturer's 300 could be softer than another mfr's 220.

[79-TA]

^ The ratings aren't verified by any 3rd party and are then by no means an exact science. However, they're not that far off.

Some people value a higher treadwear rating because they don't want their tires to wear out quickly. Others might value a lower treadwear rating as it implies a stickier compound. Because of this, there's no clear cut way for a manufacturer to cheat with treadwear rating.

[Steve1968LS2]

Is there a uniform way that the manufacturers measure the treadwear rating? From what I have been told, one manufacturer's 300 could be softer than another mfr's 220.

It was supposed to be (the U int UTOG) but in reality it's not.

It is good for judging within a company.. for example a 100tw Nitto NT01 a 200tw NT05 and a 300tw NT555.

It gets a bit more grey when you compare between companys.

Even a tire like the PS2 from Michillin has different compounds in regard to special OEM runs. That's why there are two of some sizes.

[-The Stig-]

It was 180 and they got FUBAR'd up and said "200 tread depth" which made no sense.

Then they said they meant 200 TW.. some of us argued the point since people had bought and ran 180tw tires..

It seemed silly to split hairs over 180/200 so they went back to 180..

Of course I've already gotten rid of my 180s and now run 220s.. lol.. but I'm sure some people, like Mary, are very happy they don't have to buy new tires.

Ahh, I must of missed that when they changed the rule from 180.

Never made much of a difference to me, my OEM tires on the G8 are TW140...

I'm going to have to buy some new rubber for RTTC.