im not gonna say your wrong.... BUT.... the rating has more to do with the centrifugal forces on the tires spinning at a superhigh rpm at speed. i have gone 135 on an r rated tire before.... not for long... but its definatly a big risk... they will blow


whats tfcc?

 

never seen a r-rated tire in my life. r usually means radial. s is the most common.

i've been selling tires for over 12 years. training from BFGoodrich, Michelin, and Firestone. yes centrifugal forces are another thing involved with the speed rating. the higher the speed rating, the more that is built into the tires to be able to handle the centrifugal forces and heat build up. for instance. here's a list of the most common speed ratings used in order from lowest to highest.

s= 112
t= 118
h= 130
v= 149
w= 168
y= 186
z= above 186

now starting with h, they add what's called nylon. nylon acts like shrink wrap for tires. as tires rotate, they build up heat and expand. as the heat builds up, the nylon shrinks. this helps to keep the tire from expanding in the centers. thus helping to mantain the most tread contact on the surface. you ever notice when you have s or t rated tires that no matter how well you keep tire pressure at the proper psi, they still wear in the middle?

people get hung up on speed ratings and think i don't go that fast. so, i don't need that expensive tire. and then get the lower speed rated tires. you sacrifice handling for price. even at normal everyday speeds, the higher speed rated tires will respond better. cornering, accelerating, and even braking. tires squirm and go out of shape when forces are applied to it. many tests have been done and proven that a h-rated tire will stop about 11 feet quicker than the lower s and t rated tires. in europe you cannot have a tire on your vehicle less than h-rated. even on the wife's saturn we used to have, i ended up putting v-rated tires on it. not for the amount of speed it can handle(obviously), but for the added handling capabilities associated with it. better tire is safer tire.

 

all i pretty much ever see is r tires.... no speed rating... or the baseline one anyway... 99mph? i have one on my trans am the stupid dealership put on... all my tires say 275/45/ZR17 except for that one 275/45/R17

 

ok that r means radial. you are not completely reading the entire nomenclature on the tire. http://www.michelinman.com/care/tools/sidewall.html look this over and you'll then be able to see what your tire's speed rating is. not all manufacturers place the speed rating inside the tire dimension.

the one tire that says 275/40R-17 (not 45) has the speed rating after the tire size. a two or three digit and one letter designation. the number represents the load carrying capacity of the tire. http://www.michelinman.com/care/tools/loadtable.html also putting more weight on the tire than it's rated for will increase the heat build up in the tire itself as well. the added heat will deteriorate the tire quicker over time.

 

so in link one... that tires load rating is 97.... and its speed rating is T

am i correct? *looking for a flashlight*

 

yes

 

sweetness!

its W rated

now i just have to find a safe place to top that puppy out

 

tulsa firebird and camaro club

http://www.ws6zxr.com/index_forums.php?

 

o i c