Fix A Flat - Limited Speed Range?
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From: Seattle
C-300, XC70, Wrangler
Fix A Flat - Limited Speed Range?
Sunday afternoon I noticed the RR tire was low. I noticed it because the dash went RED. Hm. I check. Yep, it was low. I got to the corner gas station and put 33 lbs in it like the door plate says. (Sticker, really.)
Monday morning it was down to about 20 lbs. I didn't drive the car, used another because I had to be someplace.
Today is was down to about 7 lbs. After I pulled out of the garage and put it in Drive, the dash went RED again. I pumped it up and took it to the tire dealer ("Big O" for those in the area). There was a screw in the tred. Easy fix. On the road again.
After the experience on Sunday, I had bought a small air compressor to sit in my trunk. Hmm.
So here's the question and point of all this: The guy at the tire shop said that Michelin claims that a fixed tire no longer has the same speed rating. What does this mean? Sure the car is limited to, what, 130 mph, and our speeds on the freeway are somewhat below 80 mph (on a GOOD DAY! Lousy days see stop-n-go!) But, what does it mean, "Limited"?
thanks
Monday morning it was down to about 20 lbs. I didn't drive the car, used another because I had to be someplace.
Today is was down to about 7 lbs. After I pulled out of the garage and put it in Drive, the dash went RED again. I pumped it up and took it to the tire dealer ("Big O" for those in the area). There was a screw in the tred. Easy fix. On the road again.
After the experience on Sunday, I had bought a small air compressor to sit in my trunk. Hmm.
So here's the question and point of all this: The guy at the tire shop said that Michelin claims that a fixed tire no longer has the same speed rating. What does this mean? Sure the car is limited to, what, 130 mph, and our speeds on the freeway are somewhat below 80 mph (on a GOOD DAY! Lousy days see stop-n-go!) But, what does it mean, "Limited"?
thanks
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Sunday afternoon I noticed the RR tire was low. I noticed it because the dash went RED. Hm. I check. Yep, it was low. I got to the corner gas station and put 33 lbs in it like the door plate says. (Sticker, really.)
Monday morning it was down to about 20 lbs. I didn't drive the car, used another because I had to be someplace.
Today is was down to about 7 lbs. After I pulled out of the garage and put it in Drive, the dash went RED again. I pumped it up and took it to the tire dealer ("Big O" for those in the area). There was a screw in the tred. Easy fix. On the road again.
After the experience on Sunday, I had bought a small air compressor to sit in my trunk. Hmm.
So here's the question and point of all this: The guy at the tire shop said that Michelin claims that a fixed tire no longer has the same speed rating. What does this mean? Sure the car is limited to, what, 130 mph, and our speeds on the freeway are somewhat below 80 mph (on a GOOD DAY! Lousy days see stop-n-go!) But, what does it mean, "Limited"?
thanks
Monday morning it was down to about 20 lbs. I didn't drive the car, used another because I had to be someplace.
Today is was down to about 7 lbs. After I pulled out of the garage and put it in Drive, the dash went RED again. I pumped it up and took it to the tire dealer ("Big O" for those in the area). There was a screw in the tred. Easy fix. On the road again.
After the experience on Sunday, I had bought a small air compressor to sit in my trunk. Hmm.
So here's the question and point of all this: The guy at the tire shop said that Michelin claims that a fixed tire no longer has the same speed rating. What does this mean? Sure the car is limited to, what, 130 mph, and our speeds on the freeway are somewhat below 80 mph (on a GOOD DAY! Lousy days see stop-n-go!) But, what does it mean, "Limited"?
thanks
Tires have speed ratings. Example...for a 225/40 VR 18 tire, the V means the tire is rated up to 149 mph and the R means Radial, of course. Other speed ratings are as follows:
S up to 112 mph
T up to 118 mph
U up to 124 mph
H up to 130 mph
V up to 149 mph
Z up to and above 149 (whatever that means)
W up to 168 mph
Y up to 186 mph, and some other Y rated tires that have limits above 186 mph.
From the tirerack website. They state it well:
In Germany some highways do not have speed limits and high speed driving is permitted. Speed ratings were established to match the speed capability of tires with the top speed capability of the vehicles to which they are applied. Speed ratings are established in kilometers per hour and subsequently converted to miles per hour (which explains why speed ratings appear established at "unusual" mile per hour increments). 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.
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.
Over the years, tire speed rating symbols have been marked on tires in any of three ways
I have driven highway speeds for many miles, up to 20,000, on a tire repaired such as yours. The manufacturer will not guarantee the tire has maintained its speed rating because of liability issues, or "they can't control the quality of the repair."
Last edited by Derspeed; Apr 1, 2008 at 01:59 PM.
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2008 C350, Obsidian Black, P2, MM, Pano, AMG Wheels, i-Pod and Leather
I've understood the speed rating to mean that you could slam on the brakes at the maximium speed rating of the tire without the tire disintegrating.
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From: Sydney
2008 C 220 CDI Avantgarde
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C350
un;ess of course its a firestone from a ford explorer
but seriously, the repair would only be an issue if you tracked your car. A proper repair will allow the tire to function properly under all but the most extreme circumstances.
