Sorry for asking guys but will h rating tires be good on a cobalt ss/sc and can someone tell me what treadwear means like treadwear 420 does that mean how much rubber is applied to the tires? thanks

 

that depends on you and how fast you like to drive at for extended periods of time.

Q = 99 MPH, 160km/h
S = 112 MPH, 180km/h
T = 118 MPH, 190km/h
U = 124 MPH, 200km/h
H = 130 MPH, 210km/h
V = 149 MPH, 240km/h
Z = 149 MPH, 240km/h and over
W = 168 MPH, 270km/h
Y = 186 MPH, 300km/h

 

well with h ratings how long can i do 147 for and ive only toped my car out twice.

 

I have no clue how long a H rated tire would actaully last @ that speed, but i wouldn't want to be the tester. Why not just get Z+ rated tire?

 

How long do you plan on going 147mph? Plan on taking a fast trip somewhere?? Your talking like your going to be setting your cruise at this speed.
It seems like you limiting yourself with the H rated tires. You'll just have to shut down a little early that's all. As long as you stay 130 and under you'll be fine. I wouldn't chance anything over that!!

 

z rating is going away silently just get w rated tires

 

the reason why is because on wheelfire.com they only really have h rating tires and there pretty cheap so i was trying to save money and get a great rim what do u guys think i should do.

i very well might spend the little extra dough on tires and get the w rated

 

here you go http://www.tirerack.com/

 

Anything Z rated and above will be fine.
I didn't know V and Z had the same rating, is that right P7X?? Oh, never mind. I see now.

 

Those ratings are off www.1010tire.com as for the H rating im sure having H rated tires would not hurt anything. Go for it.

 

If you put H rated tires on your car I would NEVER go faster then 130 MPH or you risk the tire blowing out. At 130 MPH an H rated tire is at the max for it to safely dissipate heat. Going fater then that can literaly disintegrate the tire in a matter of minutes.

 

Imnot too sure about that. When tires are given a rating that doesnt mean the moment you hit 130 mph that they will blow up. It means that if you subject them to speeds in excess of 130mph for a period of time they could fail.

 

^ ^ Yep!

 

agreed with the comments above
also, in some states you are required to buy the proper speed rating (OEM)
not sure how they enforce it, maybe inspection? just research it and be sure

 

You should keep whatever speed rating your original tires are or higher. The reason is the compound and the flex in the sidewalls. A tire of a lesser speed rating will indeed fit but the difference will be in the handling and stopping. A treadware rating of 420 is a good wearing perfomance oriented tire, but if you look at higher speed rated tires this is not the case most of the time. As a general rule of thumb when it comes to tires is the lower the treadware rating is the stickier the tire will be, but it will also ware faster. Another number that is often overlooked is the 2 or 3 digit number attached to the speed rating. Eg. 91w, 89v, 90h. these numbers reflect the overall weight of the vehicle that the tires are to mounted to. Larger perfomance luxury cars equipped with lower profile wheels can have numbers that look like....... 102W or 104Y. So if you found a tire of the OE speed rating you may be able to narrow your choices as far as which will last longer if they have the same treadware rating, by comparing the vehicle weight designation, the tire with the higher number should last longer because it was ment for a heavier vehicle.

Oh and one more thing, when comparing tires. Make sure you compare apples to apples. Comparing tires of different speed ratings is the equivilant of comparing apples to oranges.

My 0.02

 

try the general exclaim UHP's, good rating and a fair price. rated very high by tirerack! 225/40/18's thats the closest size I think!

 

Ive worked at Discount Tire too long...Any kind of tire and wheel questions, ask me. Basically for the H rated 130MPH is the max they should go. Eventhough you can go above this, its just not safe for the tire. Ive put Q rated on my Balt, which is 99MPH and drove at 104(right before the Rev limiter) the tires just get almost flat spots in them(like from skidding.)That can cause a blowout........