I too had a nail in my rear tire. I was told that if you patch a hole in a tire, even in the tread area, then you lose the speed rating of the tire and shouldn't trust it at high speeds. It should always be replaced. Is this true?

 

From my understanding, if you plug it (which is the easy way to fix a tire without removing the tire from wheel), you lose the speed rating. However, patching it from the inside is supposed to be ok. I know Discount Tire/American Tire Co use combo patches/plugs, and they do take the tire off.

I've had countless tires repaired from them on all sorts of sports cars and have never had any issues, and they've never mentioned anything about ruining the tires speed rating, and they're in the business of selling tires. I've been pretty happy with them. Also, I don't really go fast anyways; my G35 has been to 105mph once and even a weak speed rating is capable of that. It's worth noting I've driven previous cars 155+ on patched Z-rated tires, but that was in my youthful/stupid days. G35 tires cost maybe around $300 to replace and I'd have already replaced two within 5,000 miles.

 

PS - just found this: http://www.policedriving.com/article77.htm

It states (from Goodyear), the proper tire repair procedure for Goodyear to retain its speed rating.

Long story short, patch+plug.

 

Thanks for the info BrianV.