speed rating on tires

[Sups]

well i was thinking... since all tires have different speed ratings.. what does it really mean. like i was looking for some price quotes from a discount tires near my house and i asked for a quote on the kumho 712s and the guy there said that the nankings are cheaper, but have a lower speed rating. i think it was like H or something... the guy there said its up to 130mph

well my question is.. what does that really mean? i want a specific answer to this.. not just "you cant go pass 130" cuz i'm pretty sure the tires wont just go pop from 129mph to 130mph, or does it..

is it just the recommended max speed that the tires can go without a lot of significant wear and tear?

[NoCones]

read this (about halfway down):
http://www.tirerack.com/tires/tiretech/general/speed.htm

[Sacha@edgeracing.com]

Spd Rtng MPH KPH
N 87 140
P 93 150
Q 99 160
R 106 170
S 112 180
T 118 190
U 124 200
H 130 210
V 149 240
Z 149+ 240+
W 168 270
Y 186 300


generally this means that the tires will not hold up to these limits over prolonged periods of time due to heat.

[Sups]

oh ok.. kinda clear some thing in a way