Post by Phil Nottingham on Aug 8, 2005 19:38:00 GMT
SR rating is the minimum - its not what speed you do in the car, legal or not its the speed thats its capable of - I am sure the insurer would find a way to wriggle out of paying out if a lower speed rating was used and a claim was pending.
I always notify my insurers of any mods from original spec and radial tyres are just one example
Phil - 1964 P5-Coupe PMB***B & P5B-saloon LHO***L & other classic Rovers & Land-Rovers
When it’s time to replace your tyres, you have to know what brand and type you want, as well as their size. This information is printed on the sidewall. Brand name and tyre name are easy enough to find.
Tyre size is measured in a combination of millimeters, letter codes and inches. As an example, you might find the following on the sidewall of your tyre: 205/60SR15. The first number is the tyre’s width in millimeters -- in this case 205mm. The second number is its aspect ratio or the ratio of sidewall height to width (also known as "profile"). In this case the sidewall height is 60 per cent of 205mm -- or 123mm. This tyre is speed-rated, so the second letter is the speed rating-- in this case it’s "S" (180 km/h).
Speed ratings give a general idea of a tyre's overall performance characteristics -- a family sedan needs no more than an "S" rated tyre, while a Ferrari will use a "Z" rated tyre. Tyres with high speed ratings are more expensive and shorter-lived than tyres with low speed ratings. Speed ratings use the following letter codes:
Q 159 km/h S 180 km/h T 190 km/h U 200 km/h H 209 km/h V 240 km/h Z 240 km/h & over
The next letter is "R" for radial construction -- a superior design to the bias ply tyres of old.