986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Time for new tires

01-06-2006, 12:00 PM

The terminology changed several years ago. The term "speed rating" is a misnomer.

I've linked a few examples, but the industry has changed the name due to the fact that consumers tend to focus on one word that doesn't accurately represent what the rating stands for: "Speed". They see that word and say, I don't drive above 65 mph in my SL500. Why do I need a tire with a SPEED rating of 149+ mph?

http://expertpages.com/news/performance_tires.htm

8th paragraph down explains why it is now called a Performance Rating, and no longer called the "speed rating".

Same here : http://www.sizes.com/home/automobile_tires.htm

It isn't about a tire going 149 mph for 1/4 mile. Most people never go that fast, and most cars cannot go that fast. But they may still own cars with sophisticated suspensions requiring certain performance characteristics found in tires capable of sustaining a 149 mph rate of speed for one hour, under load, without compromising the performance of the tire, which is related to sidewall stability and integrity.

Performance does not necessarily mean high speed. Performance is simply how a tire perfoms under normal driving conditions. Important things like steering response/cornering, accelerating, braking and maintaining control in a panic situation. A better perfomance rating means improved response times. The sidewall doesn't have to play "catch up" under sudden braking and swerving manoeuvers in a higher performance rated tire. This would be the "slip angle", and less is better, which is what you get with a higher performance rating.

But, try telling this all to John Q. Public...or his wife. They still focus on the fact that they never drive above 65 mph and see absolutely NO reason to spend money on a tire that does. By calling it a performance rating, it emphasises the safety aspects, which John Q Public is far more responsive to.

A classic and true story about speed ratings: My husband was dealing with a Lady with her XJS Jaguar, and she thought she was All That. While my husband tried to patiently explain why she could not put S-rated $39 tires on her Jaguar, which required V-rated. She finally blurted out in a very demeaning manner (as if talking to some $5.00/hr peon), "Excuse me, but I own a Jaguar. I think I know what it needs better than you do . Have you ever even driven one?"

"Yes ma'am, I have, but I prefer to drive my Porsche or Maserati." and pointed to his car parked next to the building. That shut her up right quick.

01-06-2006, 12:00 PM	#33
creseida Guest Posts: n/a	The terminology changed several years ago. The term "speed rating" is a misnomer. I've linked a few examples, but the industry has changed the name due to the fact that consumers tend to focus on one word that doesn't accurately represent what the rating stands for: "Speed". They see that word and say, I don't drive above 65 mph in my SL500. Why do I need a tire with a SPEED rating of 149+ mph? http://expertpages.com/news/performance_tires.htm 8th paragraph down explains why it is now called a Performance Rating, and no longer called the "speed rating". Same here : http://www.sizes.com/home/automobile_tires.htm It isn't about a tire going 149 mph for 1/4 mile. Most people never go that fast, and most cars cannot go that fast. But they may still own cars with sophisticated suspensions requiring certain performance characteristics found in tires capable of sustaining a 149 mph rate of speed for one hour, under load, without compromising the performance of the tire, which is related to sidewall stability and integrity. Performance does not necessarily mean high speed. Performance is simply how a tire perfoms under normal driving conditions. Important things like steering response/cornering, accelerating, braking and maintaining control in a panic situation. A better perfomance rating means improved response times. The sidewall doesn't have to play "catch up" under sudden braking and swerving manoeuvers in a higher performance rated tire. This would be the "slip angle", and less is better, which is what you get with a higher performance rating. But, try telling this all to John Q. Public...or his wife. They still focus on the fact that they never drive above 65 mph and see absolutely NO reason to spend money on a tire that does. By calling it a performance rating, it emphasises the safety aspects, which John Q Public is far more responsive to. A classic and true story about speed ratings: My husband was dealing with a Lady with her XJS Jaguar, and she thought she was All That. While my husband tried to patiently explain why she could not put S-rated $39 tires on her Jaguar, which required V-rated. She finally blurted out in a very demeaning manner (as if talking to some $5.00/hr peon), "Excuse me, but I own a Jaguar. I think I know what it needs better than you do . Have you ever even driven one?" "Yes ma'am, I have, but I prefer to drive my Porsche or Maserati." and pointed to his car parked next to the building. That shut her up right quick. Last edited by creseida; 01-06-2006 at 12:33 PM.