Repairing Z or Y rated tires--not good?

[Ralph LoGrasso]

Well, my seemingly endless string of bad luck with my Z06 continues. I noticed my passenger side rear tire was low today and sure enough, I picked up a screw. The damage wasn't terrible and I was able to plug the tire, but I'm not sure if I'm happy having a plug in there. I'm also not going to be happy dropping $350 that I don't have on a new tire.

I seem to recall reading somewhere that it was not recommended to plug Z / Y rated tires on high performance applications. Or that it was not recommended to travel over 100mph on plugged tires. Something along those lines.

Is this true?

This car sees triple digit speeds (sometimes very high triple digit speeds) and high g-forces very, very often. I'm not sure it's safe to be driving aggressively on a plugged tire. Is it?

Would a plugged tire (albeit a small plug) pass tech inspection at a road course or drag strip? I'm thinking this would answer my question.

Any help or insight would be greatly appreciated.

Thanks,
Ralph

[Yelcamino]

Way back in the day when I worked at a tire shop, I was trained not to plug tires because the process of inserting the plug distorts the belts in the tire thus affecting the integrity of the tire. Is it fact or fiction? Beats me, that's what I was taught. IMO, on a vehicle that sees high speeds as you describe, there may be some validity to my years ago training. Any experts out there with an opinion?

[Ralph LoGrasso]

Thanks for the quick response, Herb. Unfortunately, thats not good news!

P.S. The tires are Goodyear Eagle F1 Supercars:

295/35/ZR18

220 AA A

[Yelcamino]

Thanks for the quick response, Herb. Unfortunately, thats not good news!

P.S. The tires are Goodyear Eagle F1 Supercars:

295/35/ZR18

220 AA A

I figured that wasn't what you wanted to hear!

I doubt this will make you feel any better, but I bought a brand new '98 Ninja ZX6R and after putting less than 2000 miles on it, I picked up a nail in the back tire. No big deal I thought. The next day I rolled into the local Kawasaki dealer to get the tire fixed and the dude behind the counter says: Yeah, we don't repair bike tires, we only replace them. Naturally I was thinking WTF? Their reasoning was you only have two little contact patches between you and the pavement, why take chances? So as the new tire replaced the little bit less new tire, $200 left my wallet.

[another69]

I also worked in a tire shop and was taught never to plug, but to patch (inside). It seemed like a quality repair, and I wouldn't think twice about doing it in your application. The air pressure actually pushes it against the tire, so I don't see much chance of failure.

[Boesch]

Maybe the patch/plug will be fine, but in my world I'd never run that tire in the conditions you're pushing it to. If you're running triple digit speeds the last thing you want is that plug to cause a tire failure. A tire failure at 100+ isn't going to be pretty. Extra $$ spent when your survival and life is involved is money well spent in my book.

[Ralph LoGrasso]

Thanks for the responses everyone. I've decided that I'm going to replace the tire rather than take a chance on it.

Now the question is--do I drop $359 on a new Goodyear Supercar F1 or do I drop $778 on a set of 4 Kumho Ecsta MX, which I ran on my Camaro SS and loved.

I'm leaning towards the MX'...

[Yelcamino]

Are the other three Goodyears in good enough condition to sell? Maybe you could recoup some of the cost of the new Kumhos.

[Vegas69]

You answered your own question when you said you see triple digit speeds and high g forces. My life it worth more than $350 bucks. I'd atleast patch it.

[Restomod]

Yeah if you were just driving it and doing burnouts I would not worry but you said you really drive it so a new one is in order. BTW A couple burn out pics would be cool.......

[86Cutlass383SR]

I do tire work for a living. When you do a repair, it basicaly voids any speed rating. Whether you plug or patch, at higher than normal forces are trying to rip the tire apart and the first place that tire will fail is the repair.

For normal highway driving the tire would be fine. For high speed, replace it. Your life is worth more than that tire!

[JRouche]

Guess Im gonna buck the trend here.. I would say a "patch-plug" from the inside isnt goona make you wreck, your driving might J/K

But honestly, a small 3/16" hole (for the plug) through the wire of the tire isnt gonna make the entire tire unravel. Thats just comical from my seat. The GY tires are rated at that speed for rubber compound and heat ability. That tiny hole though the core wont make it fail. Now, GY may say yes, replace the tire, well, thats good business. But from the sounds of it you are ready for new tires all around right. In that case yeah, nothing better then some new rubber..

But if it was a 75% tire would you be asking??? Cause if it is a 75% tire, that much left, then all the rest are that good too right?? You gonna scrap them or sell them )))

My point is what if it was a brand new tire?? Fifty miles on it. Then what, does your decision change?? JR

[JRouche]

I do tire work for a living. When you do a repair, it basicaly voids any speed rating.

Now thats interesting. Void the speed rating. What does that mean???? I really didnt know there was any guarantee to void. Do they give a warranty that the tire will rotate at the speed rating??? LOL The tire manufactures dont hold ANY guarantee that your tire wont separate at speed. Insurance policies dont go that high, ask Firestone.

No, if yer tire flips out at 135MPH and you go to GY and say hey!!! WTF! Where is my warranty or worse yet. Here is my bill for the wrecked car and my crippled body they will ignore you. There is NO guarantee for high speed tires, not like that... JR

[86Cutlass383SR]

With the added heat and the forces trying to rip the tire apart in general, any puncture would be the first place a failure would start.

We do use the "plug-patch" method. Drill the puncture out, buff, and then glue for the plug-patch. You are simply plugging the hole so it don't leak. Good enough for normal highway driving. But, do you want to be running 130-150 mph and wonder, "Is that patch really good enough?"

Not in my mind and I've done tire work for several years. I'm not saying it's guaranteed to fail. It may not. But if it does...

[86Cutlass383SR]

Speed ratings as explained by Tirerack.com:

Speed ratings are based on laboratory tests where the tire is pressed against a large diameter metal drum to reflect its appropriate load, and run at ever increasing speeds (in 6.2 mph steps in 10 minute increments) until the tire's required speed has been met.

It is important to note that speed ratings only apply to tires that have not been damaged, altered, under-inflated or overloaded. Additionally, most tire manufacturers maintain that a tire that has been cut or punctured no longer retains the tire manufacturer's original speed rating, even after being repaired because the tire manufacturer can't control the quality of the repair.

[86Cutlass383SR]

Notice it doesn't say warranty or guarantee?

Here are the speed rating in case anyone wants to know. Again, straight from the Tirerack.com website.


"S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars

When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of new vehicles that have extremely high top-speed capabilities.

W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars


While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed.

Despite the tire manufacturer's ability to manufacturer tires capable of high speeds, none of them recommend the use of their products in excess of legal speed limits.

The maximum operating speed of a vehicle must be limited to the lowest speed rated tire on the vehicle."

[JRouche]

Hey Doug. Bunch of great info.. Yeah, you prolly wont see any racing teams using plugged tires, be like asking them if they want retreads LOL Would hate to see a guy wreck his ride do to a plug. Wonder if there is any stories of it happening. Not that anyone wants to be the 1st story either. Thanks for all the info JR

[Ralph LoGrasso]

Are the other three Goodyears in good enough condition to sell? Maybe you could recoup some of the cost of the new Kumhos.

Great minds think alike. The other three tires are in great condition, as is the 4th one sans the plug. I measured the tread on the non-punctured rear tire yesterday and it looked to be about 6/32". New is 8/32". I need to take more accurate measurements of all three good tires.

At this point, I'm thinking I'll sell the three tires and throw in the plugged one for free, so they're a "complete" set.

[Ralph LoGrasso]

Yeah if you were just driving it and doing burnouts I would not worry but you said you really drive it so a new one is in order. BTW A couple burn out pics would be cool.......

If I wind up not selling the tires, then this is the plan...

[MrQuick]

I would stay away from high speeds so its good.

Note, if a Viper comes to the shop with a nail it gets a new tire and I get a new mock up junker. LOL