205/40/hr17?

I know the R is for radial but what does the H stand for? And what’s the difference between the HR and the R rated tires.

speed rating.

What about all those letters? V, H, Z, etc.? These are speed ratings to show what kind of speed the tire is capable of handling without breaking down due to heat. Here they are:

N = up to 87 MPH
P = up to 93 MPH
Q = up to 99 MPH
R = up to 106 MPH
S = up to 112 MPH
T = up to 118 MPH
U = up to 124 MPH
H = up to 130 MPH
V = up to 149 MPH
Z = up to 149+ MPH
W = up to 168 MPH
Y = up to 186 MPH

that info is right from www.team-integra.net

this site has some good info.

http://www.sbcc.ca/tech/tires1.htm

I know about the speed ratings guys, it’s just weird that the H speed rating is the only rating put before the R.

http://www.mastercareusa.com/tires/catalog/bridgestone-potenzare950.jsp

towards the bottom in the yellow, the 205/40R/17 and 205/40HR/17