Tire Repair

[ChuckV10]

I recently purchased a 2000 Boxster which came with Michelin Pilot SX tires on 17" rims.

This evening I noticed the right rear tire looked low. Upon closer inspection I discovered a nail in the tread.

The question:

Is it OK to have this repaired, or do I need to replace the tire?

If I have it repaired, what might happen if I try to take it anywhere near 150?

What about if I try a driver's ed. event?

This is my first Porsche and my first performance car.

Any thoughts would be greatly appreciated.

Thanks

-Chuck

[adsach]

In the tread is not too bad. I have been over 130MPH multiple times on a tire repaired after a simple puncture (nail between the tread blocks on the second row of tread). I did that 6th gear upshift at an indicated 150MPH once on this tire, but it was only briefly(it started to rain) and I can't recall whether that was before or after the puncture repair.

In the sidewall is hopeless. The tire must be replaced and all responsible tire stores will tell you no when you ask to repair it.

[MNBoxster]

Hi,

Once a Tire has been punctured, even though it can be repaired (if a Tread Puncture only), the Tire has been compromised and should NEVER be driven at excessive speeds. Once a Tire is repaired, it's ability to shed heat is also impaired, especially in the area of the repair. Driving at excessive speeds can heat up that part of the Tire to where it can delaminate or a Blowout can occur and is simply Foolhardy and irresponsible. You don't want either of these things happening at high speed.

There is only 1 proper method of repairing a Tire. The Tire must be plugged, but also patched on the inside[/u] over the plug. A plug alone should never be used and any shop performing such service should be avoided. The Tire must be demounted and visually inspected on the inside to insure that there is no damage to the cords, if so, replace the Tire. See the NHTSA's recommendation on Tire repair here: http://www.nhtsa.dot.gov/cars/testing/ncap...MaintRepair.htm

Now, considering that you are going to have the tire demounted, repaired (if possible), remounted and balanced, this will run a few bucks and you still end up with a compromised Tire. If your Tires are more than halfway to the treadwear bars, it may be best to hink about replacing the Tires, at least on the affected axle, especially if you are going to drive at high speeds.

Even if you are willing to take the risk, consider that you are also asking everyone else to unwittingly take the risk with you. Personally, I don't think it's a risk worth taking...

Happy Motoring!...Jim'99

[GaryFB]

Hi Everyone; what MNBoxster is saying is correct, and no repair shop should ever make a "plug" only repair. Having said that, you can purchase tire plug kits and make your own repair, and you will not even have to remove the wheel from the car. That should be considered a temporary repair, and you are accepting all liability and risk.

[ChuckV10]

Thanks for all of the replies.

Upon further examination, the tires appear to be 6 years old based upon the date code.

Even thought they have probably lived most of their life away from direct sun, I do not think that I would feel safe pushing them hard on a track or off.

Since I didn't even make it a whole week after purchasing the car without a problem, I elected to take the cheaper, path with the scrutiny of the other 1/2 of the budget committee and had the tire patched.

I plan to continue to drive on these tires as a daily driver and then when I get the car out again in the spring I will look at a new set.

Temperatures for regular the driving I do should not be very high compared to what the tires were originally designed to withstand and this will allow me to plan for their replacement.

Any thoughts on moving up to 18" from 17" rims? What about the Goodyear Eagle F1 GS-D3 tires? The car does not appear to have traction control and the primary use for the car is daily commuter over somewhat rough mid-west surface streets. I would eventually like to try a drivers ed event or maybe a little auto-crossing, but my schedule will likely permit only a few of those each year.

Thanks again for the comments.

-Chuck

[adsach]

...

Any thoughts on moving up to 18" from 17" rims? What about the Goodyear Eagle F1 GS-D3 tires? The car does not appear to have traction control and the primary use for the car is daily commuter over somewhat rough mid-west surface streets. I would eventually like to try a drivers ed event or maybe a little auto-crossing, but my schedule will likely permit only a few of those each year.

Thanks again for the comments.

-Chuck

<{POST_SNAPBACK}>

The main advantage of 18" over 17" is the slightly wider rims as shipped by Porsche. The wider rims support slightly wider tires. The lower profile tends towards more sidewall stiffness, which helps cornering.

For Drivers Ed, while a 225 in front is noticeably better than a 205 - for the first 15-20 track days there are plenty of other things to learn that the difference isn't so important. You will get more out of an aggressive alignment or lowering springs than 20mm wider tires.

For autocross, nothing beats a fat tire. Premium autocross wheels would probably be lightweight 17x8 front 17x10 rear (i.e. 996 5-spoke lightweights) with spacers. The 17" wheel gives one more tire choices than 18" wheels - especially in R compound, Falken Azenis, etc.

17" tires are less expensive. If you actually do 2-3 days of DE, 2-3 Autocross days and daily driving, you will be buying AT LEAST one set of tires a year. The cost of 18" wheels can add up.

18" tires are bit hard on potholes. The sidewalls are stiffer. This is good for performance but jarring for potholes. In Arizona, which has virtually no potholes, this does not matter. For the East coast, this took some getting used to. For the snow and slush months, where potholes are often hidden, I have 17" snow tires

[Rolando]

Hi Everyone; what MNBoxster is saying is correct, and no repair shop should ever make a "plug" only repair.  Having said that, you can purchase tire plug kits and make your own repair, and you will not even have to remove the wheel from the car.  That should be considered a temporary repair, and you are accepting all liability and risk.

<{POST_SNAPBACK}>

Modern tires are designed not to blow out even it they have a nail in them. The tire integrity should be better whith a well repaired puncture than with the nail in it. If we worry about a repaired tire we should be constantly worry about stepping on a nail and driving with it and should stop every few miles to check the tires. :rolleyes:

Of course raising protocols are a different issue ... I can't imagine anybody paricipating in NASCAR with a patched tire. :wacko:

[GaryFB]

Hi Everyone; what MNBoxster is saying is correct, and no repair shop should ever make a "plug" only repair.  Having said that, you can purchase tire plug kits and make your own repair, and you will not even have to remove the wheel from the car.  That should be considered a temporary repair, and you are accepting all liability and risk.

<{POST_SNAPBACK}>

Modern tires are designed not to blow out even it they have a nail in them. The tire integrity should be better whith a well repaired puncture than with the nail in it. If we worry about a repaired tire we should be constantly worry about stepping on a nail and driving with it and should stop every few miles to check the tires. :rolleyes:

Of course raising protocols are a different issue ... I can't imagine anybody paricipating in NASCAR with a patched tire. :wacko:

<{POST_SNAPBACK}>

Hi Rolando; There are at least 3 types of tire puncture repairs. 1) is the plug only, installed from the tread side. 2) is the patch repair, installed from the inside of a dismounted tire. 3) is the one piece patch and plug, installed from the insdie of a dismounted tire. I will research and report back as to with Federal or Industry agency has ruled that only #3 is an acceptable repair. From a liability issue, #1 and #2 should not be performed by a repair shop, moisture can leak in and corrode the belts resulting in a tire failure.

If the vehicle owner installs #1 or even the liquid stuff through the tire valve, that is ok. But when a repair shop performs this operation, and an accident results, the repair shop is liable because the industry says that #1 and #2 are not acceptable repairs. If it goes to court, the repair shop loses.

If you like, I can obtain more information. I have done many #1 repairs without out consequences, even on race tires. But in the eyes of the law, those were not acceptable repairs.

I think it might be 2006 model year cars will be required to have tire pressure monitors as part of the EPA vehicle emissions requirements. Low tire pressures reduce fuel economy and increase emisions per mile. Some vehicles use the ABS sensors to detect deflating tires.

[Rolando]

Completely agree with you Gary, I had my two back tires repaired last week, the tire shop explained the proper procedure of plug + patch. #3 is what I ment when I mentioned a "well repaired puncture".