The importance of speed rating for MB - PeachParts Mercedes-Benz Forum

brianw · #1 03-21-2003, 07:10 PM

I've been searching and cannot find the answer to a question. How important is the speed rating for my CLK? It is not my daily driver, I only drive it on sunny days with an infrequent road trip that might see rain. Is it necessary to drop for the Z rating over say a Y or W rating.

I understand that the Z will be "safer" or "more stable" at higher speeds, but I seldom drive over 85-90 for any period of time. Do I need to buy Z rated tires. How much of a difference is there between W - Y - Z? Do different cars (weight) required different speed ratings? What factors determine the type of tire I should buy? Price, driving habits, road conditions, car weight. This is assuming all tires being considered are performance tires.

Thank you!

manny · #2 03-21-2003, 08:39 PM

May I suggest www.tirerack.com.
You may as well get facts, rather than opinions.

brianw · #3 03-22-2003, 04:59 PM

Yes, I called the Tirerack which is why I posted here. The gentleman I spoke with told me his suggestion was the S03 PP because they were Z rated. I asked why I had to have Z rated tires and he told me because they are safer and more stable at high speeds. I told him I rarely drive over 85-90 but he would only recommend the S03's. Not matter what my question was, his response was Z rated tires...S03's.

That's why I asked here to find out why the only tire he would suggest is the S03's. I felt as though he was digging for a commission.

Thank you!

manny · #4 03-22-2003, 09:49 PM

Quote:

Originally posted by brianw
I felt as though he was digging for a commission.

Nooooooo kidding.
What speedrating did the car come with ?
I would look at the speed rating chart, maximum load rating & general comments/reviews, and pick a tire that sounds good.
Can't see why a " V " rated tire would not suffice.
Like I said before, now you're getting opinions.

Mick J · #5 03-23-2003, 03:11 AM

If you fit tyres of a specification less than the cars capability or manufacturer's recomendation then, should someone steel it and have an accident causing injury to someone else you could find yourself at the wrong end of a law suit.

Even more so if you sold the car.

manny · #6 03-23-2003, 11:17 AM

Now there is a " politically correct" answer.

brianw · #7 03-23-2003, 03:14 PM

Now there's a sad commentary on the American public. So a "W" rating, up to 168mph, or higher should be fine. The car came with Kumho's when I bought it. I don't know what came on it as OE, probably a "Z" rated tire. I doubt every car that came with a Z rated tire all still have a Z rated tire.

400E · #8 03-23-2003, 05:47 PM

Quote:

Originally posted by brianw
Now there's a sad commentary on the American public.

Look at Mick's location -- he's from the other side of the pond ...

Badinfo · #9 03-24-2003, 06:05 AM

but hey, mike has a point! Remember that theif who fell through a poor sap's roof while trying to break in through the skylight? He got awarded some ridiculus sum of money cause he hurt his back in the fall...

Luke@tirerack · #10 03-24-2003, 08:11 AM

Quote:

Originally posted by brianw
I felt as though he was digging for a commission.

Thank you!

I do not know who you spoke with but, I assure you we are not all that way .... the minimum speed rating that is acceptable for your CLK320 is "H" and for the CLK430 "V"

need2speed · #11 03-24-2003, 10:22 AM

Quote:

Originally posted by brianw
I understand that the Z will be "safer" or "more stable" at higher speeds, but I seldom drive over 85-90 for any period of time.

Brian, would you bet your life on your "average" driving style? Its been said often before....tires are the most important safety feature you can invest in. Funny how we might spend thousands of dollars on fancy rims but hesitate at spending equal amounts for the tires that actually hit the road!

The differences in carcass/tread design and construction make higher speed-rated tires better suited for the heat that builds up while driving within their speed limits. AS A MINIMUM, you should match the factory-recommended speed rating. If you intend to exceed the limits of that speed rating, even occasionally, then you MUST buy the higher-rated tires.

I've had a tire blow during an autocross and shudder to think of the same thing happening at 100+mph or in traffic!

A fellow racer had a tire blow at 150mph during a competition two years ago and is still recovering.

Anyway, with proper rotation and alignment, you can make those expensive tires last quite a while.

Good luck with your choice.

brianw · #12 03-24-2003, 02:33 PM

Luke,

I didn't mean my comment to be inferred negatively, but I just wanted to know why others are buying W and Y rated tires for the CLK430 and I couldn't get a straight answer as to why. I was simply asking for my edification and just felt the salesman was not answering my question and letting his commission get in the way of the answer. Not a criticism, just an observation. I tried calling you first and was out of my office when you called back, then received another gentleman when I called back.

Dean,

Thank you for your insight and have purchased nothing but Z rated Michelins prior and also believe tires are the most important safety aspect of driving...and brakes. I see others buy varying types of lesser rated tires and just wanted to try a set of W or Y rated tires to see what difference there was relative to the Z rated tires I have purchased prior.

Thank you all for your responses! I'm going to give the HTR ZII's a try. After these I'm going to try the Bridgestones.

need2speed · #13 03-24-2003, 08:02 PM

Quote:

Originally posted by brianw
I see others buy varying types of lesser rated tires and just wanted to try a set of W or Y rated tires to see what difference there was relative to the Z rated tires I have purchased prior.

Of course, W and Y-rated tires are for higher speeds than Z-rated. When you read the sidewall it will likely have the size listed, for example, as 245/45ZR-17 but that will be followed other smaller coding that will indicate W or Y speed rating.

blackmercedes · #14 03-26-2003, 12:28 PM

Years ago my wife and I were making a high speed dash from Bakersfield to Vegas. It was 45C.

She had nagged at me for buying V-rated (Z was way out there) tires for the 16V.

As we tore across the desert we came upon dozens of cars with tire problems. She wondered aloud why we seemed to be doing so well. I explained that the V-rated tires were built to withstand much higher temperatures, as generated by high speed running.

Now, she INSISTS that we buy premium tires, and pay close attention to speed ratings. As we whistled by car after car on the roadside in the extreme heat, she finally got it...

Chiragp · #15 03-27-2003, 10:15 AM

But I thought many tires that are rated (say H-rated at 130mph) can handle upto 130 mph, but thats if the PSI inside the tire is raised. If you run on the stock psi, then your actually lower then 130, mor elike 125.

I've been told more powerful/sporty cars require higher performance tires because even if you don't drive at that speed, the more performance oriented tires stick better. now I'm sure you don't corner hard like some of us might, but just imagine your tire spinning in the rain under acceleration or snow or something...When that tire speeds up...its hitting those speed rather quickly sometimes without you noticing...which leads to blowouts...Granted maybe a rare or extreme "what if"

but there are many others...such as your emergency handling is compromised as well as dynamics of the car because these cars were designed to take advantage of the rubber and grip that comes standard. Goign below that is asking for trouble.

Now my rule of thumb, (even for my father's car) is at least H-rated. Only reason I say that...is its a nice balance. The Temperature rating is still A (going lower then A gets a B)

recomendations:
clk with 16" wheels: You sound like you don't need the extra rubber...so 205/55/16s should be fine although going to 225/50/16s shouldn't pose any problems.

http://www.tirerack.com/tires/tires.jsp?tireMake=Continental&tireModel=ContiExtremeContact&vehicleSearch=false&partnum=055VR6CEC&f romCompare1=yes

for $69 each you get V-rated Directional tires in anUltra High Perfomance All-Season category with a tread wear rating of 400 A A...sounds like a tire that will last slightly longer then many others.

runner up choice: Dunlop SP Sport A2...comes with a 50k mile warranty...

For the 17" sport packaged tires:
Try a look at the Sumitomo HTR+...I've always been closed minded too them until a friend got them on his Audi A4 (with 245/40/17s all around) and I was amazed. When he told me they came with a 40k mile warranty through NTB I was furious...And they are all-season...though I wouldn't trust anything but light snow with them on my mb or bmw, but because he had quattro he was fine with them. I now have them on my 190E...I can say they don't offer Michelin Pilot grip, more like Ultra High Performance All-season grip...which they are...but they still work well, and are W-rated.

at $101 front, and $107 rear...its a decent price.

http://www.tirerack.com/tires/tires.jsp?tireMake=Sumitomo&tireModel=HTR%2B&partnum=245WR7HTRPL&partnum=44WR7HTRPL&vehicleSearch=tr ue&index=4

I wouldn't trust them for any true hard cornering that you might find on the track, but for normal high spirited street use....I think they are fine...and I'm a control freak with an M3 too