Jeff928S4

So.....I drop my car off at the local tire place just a while back and ask to have some prices on tires for the rear of the 928S4. I find a nice pair that are more than reasonably priced and ask "what is the speed-rating on these tires?". The fella tells me "......up to around 270 klms".

I get 245/50-16's put on (supposed to have 245-45-16). I figured that extra size difference wouldn't matter much. Anywho - I get to this computer to check out the specs on the tires I got and they are apparently only "S-rated", which according to some sites means they are only speed-rated up to 180 klms. Booo!!! Now I know why they were so reasonably priced!!

Now - I rarely ever go over this speed.....maybe one a month, if that. My question is, should I just take these back and get a better tire or can I use these for my purposes? How safe is it to have these tires on the car and if I ever did go 200 klms, would they blow up? (bare with me - I know NOTHING about tires).

Here is a link to the tire I bought....
http://www.hankooktireusa.com/produc..._ID=17&CatID=5

blau928

If the tire salesperson told you it's rated for 270km/h and the tire says 180... You just got suckered... actually, you should have read the tire label.. It would be clearly marked on the side.. The store if reputable should change them or offer you some sort of deal..

If you don't ever drive that fast, then nothing to worry about....

I would not drive 250 km/h on tires rated for 180... unless I wanted the tire to balloon and send me into the airline business... Then again, maybe they made the tires with a superior compound and stamped them with a lower rating....

You might want to check out the OD overall diameter of the tire to see if the size is within Porsche Spec for the speedo... 245/50 are taller than 245/45 on the same rim and same pressure....

HTH,

hinchcliffe

You should be fine. Just pay attention to your speed. Look at tirerack.com and figure out the speed rating to see what S-rated is for. If you never really travel that fast I wouldn't worry about it. If you find yourself getting near that area of speed, the tires could b eunstable and may blow out at which point you'll be kicking yourself, literally. So if you plan on going fast in the future trade out the tires, otherwise watch your speed.

I've done 130 on H-rated tires without thinking and they were stable but very uncomfortable when I remember I was on them.

Adam C

Give me a break! This is a high performance supercar. It doesn't matter how fast you drive. Tires, IMHO, are not the place to save a few bucks. That car should have the correct tire which includes a 45 aspect ratio and a Z speed rating.

Also, going to a higher aspect ratio will worsen your handling - take 'em back and do it right.

Adam C

Plus you said you only got rears, which is a no no unless your fronts are of the same make. You should avoid mixing brands on the same car.

heinrich

S-rated tyres are fine for driving a Buick, or driving a Porsche like a Buick.

sublimate

If they won't exchange 'em, go back when they're closed and do donuts in their parking lot. Then find another shop and get some real tires.

Jeff928S4

I was thinking along these exact lines. I am trying to save a few bucks, but that isn't really an option in my case. It's a 928....period - there is no way around the fact that it needs good tires, or I'll have to drive it like a Yugo.

I will take these tires back and get a better quality tire. Just for future reference, what do I look for on the tires itself to indicate speed-rating?

Also, seeing as perhaps the 245/50-16 may not be a good idea, I was curious if anyone has put the 225/50-16 on the rear to match up the front and back?

Green Goblin

Not only do they limit your top speed but it also changes the handling of the car. A V or Z rated tire has a stiffer side wall. You should run the same speed rating at least on front and back.

AO

Here. Look at this.

AO

"Z rated" for you which really means W or Y rated. Maybe V rated at a min.

WER

Take a look at the Yokohama AVS ES100, not very pricey, but seem to work fine, other than the fact mine are a bit noisey. And they come in the right size and speed rating. The 928 is a heavy car by sports car standards and the wrong tires really don't work. I found out the hard way when I put some inexpensive Bridgestones on (just for a while, till I got some new wheels) and they drove me crazy. The sidewalls were so soft that I could feel the car squirm on heavy cornering and braking, so now I have an almost new set of 225-50-16s cluttering up my garage.

Garth S

Hey Jeff,
Followed your link - and it mentions only 15" 'S' rated tires: it would be unusual to have a 245/50R16 in a 'S' speed rating from any manufacturer, unless it were a true M&S or RAC snow rated tire - but stranger things have happened. Before I say more, could you read the exact code on the sidewall, or specify the tire model.
BTW, a 245/50 will work just fine - as far as dimension goes: yes, a 225/50 will also work on the 8" rears, but 245/45 or 245/50 is 'mo betta ...

Bill Ball

I second the Yokohama ES100. Best tire in the under $100 class. W-rated (168MPH). They aren't super sticky (as you would expect), but pretty good judging by my backroad runs. They are a good overall compromise in terms of handling, wear, noise. I've used them for the last 2 years since they came out.

Mark

ANOTHER vote for the Yoko's. I have them on both my cars, and love them. (As to the noisy - in my exp, the only get that way once they've worn down about 40-50%....then not bad. And they have a very aggressive-looking tread. For the $$ - they are GREAT!

One thing that confuses me on the YOKES. They are sold as a "W-Rated" tire, but when you get them, they are marked "Z". Either way, they are the best tire for the $$!

The Hankooks you are running.....THey are fine for 'regular' usage. I have several friends that use the HRII's (One step above yours) for DE's because they're cheap. Never any problems. I have a set of the HRII's that I ran on my 951 until recently (I got new wheels that came with Yoke's on them!). They were EXCELLENT on the highway and around town. VERY quiet, and no tram-lining....Quite good in the wet, also!

BUT - as said by earlier poster's...I would NOT run different tread designs front/rear, NOR would I go to the 225 on the rears. The 245/45's are available in the Hankook HRII's AND the Yokos.