wantone

Some dude told me that and just wanted to ask the experts here... I've never seen a Y rated tire in my life!

dangarza

My understanding is that some time ago they came with the "ultimate" speed rating (Z).
Such tires are supposed to tolerate sustained speeds of over 150 MPH.
No one thought that commercially available tires could get any better than that.
Well...guess what, they did, but since there were no letters left, they had to go backward and use Y, and even W.
Jim or Xviper or any other tire guru out there correct or amplify my comments please.
PS: Love your posts wantone. Keep 'em coming.
Daniel

The Gasman

I think ours are W rated.

Q Up to 100mph Never mix and match tires with different speed ratings on your vehicle. This will cause serious problems with the handling of your vehicle.
Remember, the speeds are test speeds, not recommended speeds.

S Up to 112mph
T Up to 118mph
U Up to 124mph
H Up to 130mph
V Up to 149mph
W Up to 168mph
Y Up to 186mph
Z 149mph and over

This info is confusing though. I don't know if that Z explanation means unlimited.

The Gasman

More reading indicates that Z does mean above 150mph and is substitued when a rating such as w or y bears a loaded vehicle.

SPEED RATINGS CHART
SPEED
SYMBOL SPEED
MPH SPEED
KPH
M 81 130
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*(VR) 149 240
W**(ZR) 168 270
Y**(ZR) 186 300

wantone

So Z is not the best???

koala

All they're saying is that Z is good for 149 + but they don't know how much better than 149.

Y is the "best"

DJSang

haha, what's the "best"?

Asura

Y and W are also considered Z but not the opposite. Z used to be the highest rating before Y and W were added. FWIW, the R compound tires I have are Y rated. Ev, best is a relative term. Best for dry traction, wet traction, race track driving, autocross etc..

RWD_RCKT

Ev,

What you should actually look for on a Z rated tire is the load rating (usually right next to the tire size). If it is a recent tire, it should have it.

For example

225/45ZR/17 92W

Obviously the 225/45/17 we know about
92 is the load rating... don't ask me what the hell it correlates to. I just look at the side of the tire for max loading and pressure anyways.
Then the W is the speed rating.

Gernby

I agree with Asura. Speed rating doesn't have much to do with quality or performance. It has to do with maximum rotational speed before the tire tears apart. There are plenty of sucky tires that are Y, W, and Z rated. A lot of autocross tires used to be H rated.