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View Full Version : Do tire speed ratings mean anything?


60wag
09-04-2010, 06:42 AM
More of a question for car tires rather than offroad light truck tires, but does a W (168mph), H(130mph) or V(149mph) rating really matter or is it just a marketing gimmick to put a premium price on some tires?

I would expect that a tire that could run at 168mph continuously and not overheat would have a different rubber compound than a lower speed rated tire. But what does that mean at 70mph? Does the high speed tire have worse traction to achieve the lower heat build up? Isn't the factor of safety designed into tires so huge that the speed rating is mute?

I'm actually looking for snow tires for a SAAB and find the array of choices offered by even a single manufacturer amusing. It seems like the tire manufacturers have too many people in the R&D and marketing departments and the result is product overload that assures that most consumers simply buy whatever the tire store has in stock.

nuclearlemon
09-04-2010, 07:44 AM
not quite sure, but the socal timing association thinks so....you must have appropriately rated tires to race at bonneville. my old boss raced last year and spent a fortune on (99y) tires. he made it to 186 before blowing a turbo line, but the tires held up ;)

Jacket
09-04-2010, 09:16 AM
I've often wondered this myself. Tirerack has a decent article on speed rating that basically indicates its use was for European high speed driving, and the top speed of the vehicle.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35

Seems like if yours is a local commuter, you could probably find the lowest speed rating possible for the tire size you need.

nakman
09-04-2010, 10:04 AM
imno (n for naive) it's more of a balancing issue, so the higher speed tires are more concentric or something ? total speculation tho

nuclearlemon
09-04-2010, 10:56 AM
compound is different in some of the higher rated tires, i can't say all for sure tho

TIMZTOY
09-04-2010, 03:55 PM
It only matters If you have a car that can go that fast. If you put r rated tires on a corvet and went 150 the tires would blow up about 120. Exc exc. Sports cars need the higher rating tires for when the owner gets a wild hair. A d floors it. Now at 70 it dose t matter at all. Because they all do 70. But the higher speed rated tires are also softer which means they ware out faster.

Corbet
09-05-2010, 09:18 PM
Also plays a part in the cornering of a vehicle, not just flat speed. The higher rated tires will generally corner better. IMO I would not drop down more than 1 speed rating for summer tires. You need to keep in mind the suspension is designed around a specific tire type. To get the most of it you need the tires to match.

Hard to match it sometimes on winter tires. For example our Subaru asks for V rated. Not may snow tires for 149 MPH.