C5Dobie

My 03 C5Z has the goodyear F1's on it, but I'm not 100% positive they're the original tires, when I purchase the car it had 12,900 miles on it, so that could very well be the case.They have at least 50% tread left (I am trying to get that down) and are wearing perfectly evenly.

At any rate - is there a way to tell the age by looking at them, like a build date code?

As far as traction goes...I have nothing to compare it to. My previous muscle cars (bolted GTO and G8 GT) had narrower rubber, more weight, and less torque and I have run Toyo T1's and Hankook V12's on those along w/ bridgestone potenzas. Both cars could easily break the rear loose, but in much more predictable manner (w/ 0% tq mgmt, nearly full shift torque, and custom tune the bolted G8 GT A6 would get sideways on the 1-2 and either chirp or squirm on the 2-3, but like I said in a predictable "fun" manner) The C5Z on these goodyears goes from traction to no traction back to a neck snapping full traction like a light switch.

My Z will obviously break loose w/ ease in 1st, but is it normal at basically stock power levels (vararam/tune only mods) to break loose on a WOT roll from 2nd onto the highway? I noticed I am spinning in place at the higher rpm range when it is cooler out...I'm guessing the answer is NO. The car has even gotten squiggly on a WOT 2-3 shift on the highway, which is unsafe to put it mildly.

Once the tires are warmed up and/or the temps are warmer though, the tires seem to perform fairly well especially in cornering...if I get rid of these and run the Bridgestone RE760 (I think) in stock size will I actually be giving up performance compared to the old goodyears?

I still have yet to pull the trigger on new rubber, and I like the stock rims, but I'm at the point I think it may make more sense to just buy an 18/19" staggered setup to open up much more tire choices in the long haul....I know everyone recommends the Nitto NT05, but #1 they're not easy to find (go ahead and recommend a spot if you can) and #2 I imagine I won't get much more than 10,000 miles out of them AND I am guessing they'd perform even worse than the old goodyears in cooler weather and/or rain.

Just how much of a step down are the RE760s?

95rtturbo

I have the RE760s... They aren't the best performing tire out there, but they are definitely not a step down from what you have on the car currently. The performance is good for the money, and they come in stock sizes.

dan1546

There is a 4 digit date code on the sidewall. First 2 numbers are week and second 2 is year. It is usually in a circle near the DOT information.

For what it's worth you are going to have significantly less traction when it's cold out on a summer tire then when it warmer. Also your car will make more power when Temps are cooler. The age and condition of your tires will also play a significant role. My car breaks 1st regardless of temp but 2nd is usually OK when warm but spins constantly in cooler temps. This is with Michelin PS2s.

Sigforty

Here is a link to Tire rack with some information and pictures. pre-2000 tires have a different number setup.

http://www.tirerack.com/tires/tirete....jsp?techid=11

04silverZ06

On the F1's there is a 4 digit code stamped in an oval area on the sidewall. Mine are 3709 for example which means 37th week of 2009. So obviously not the original from my 04Z but being about 5 years old they hold very well in the corners for the street. Straight line is still decent if warmed up with about 7/32" tread still remaining. I'm not throwing these out until I find a tire that fits and works well.

pewter99

the KDWs I have on my 99 are 5 years old and are showing their age even though they have some decent tread life left ......been driving it more to offset the difference

interestingly enough the fronts are the same age but don't show it

spdrcr

The date code provides the date of manufacture. However, it depends on how the tires were stored and when they were installed as to how they wear and age.

C5Dobie

Yeah I get all that, I'm just not so sure these Goodyears are "junk" as many are quick to say. It takes alot to get them warm...i usually throw it in competitive mode and do some controlled drifts to help speed up the process, but I don't want to drop $750-$1500 on a new set of tires and not have a noticeable improvement in traction...that'd just tick me right off lol!

spdrcr

As I mentioned above, you'd have to know when they were installed on the car and put in service to determine if the age of the tires is a significant factor. It's really the UV exposure that ages the tires prior to typical usage wear.

racebum

date code tells all

if you have oem wheels the great debate is what to put on them

the supercar fell off in traction after a year to 18 months, one of the fastest aging tires i have ever encountered regarding falling off