Speed ratings for tires

[SergntMac]

This was contributted by Toddalanfisher in a thread regarding a change in speed ratings on production MMs. I reposted it here for reference, but he did the work.

"See chart below for speed ratings per your question of "W" rated tires...

Speed Rating - Miles/Hour - Kilometers/Hour - Typical Use
N=87 MPH, 140km/h, Spare Tires
P=93 MPH, 150km/h
Q=99 MPH, 160km/h, Winter, LT Tires Cars
R=106 MPH, 170km/h, LT Tires
S=112 MPH, 180km/h
T=118 MPH, 190km/h
U=124 MPH, 200km/h
H=130 MPH, 210km/h, Sport Sedans
V=149 MPH, 240km/h, Sports
Z=149 MPH, 240km/h and over, Sports Cars
W=168 MPH, 270km/h, Exotic Sport Cars
Y=186 MPH, 300km/h, Exotic Sport Cars

Hope this helps, Todd"

[looking97233]

Okay since our stock tires are W rated, that makes the Marauder an exotic sports car.

[TAF]

It is as far as I'm cooncerned...

[LincMercLover]

They are?!?! Umm... someone double check that cause I'm pretty sure they're Y.

[TAF]

From Tirerack.com

BFGoodrich g-Force T/A KDWS - Size 245/55WR18
$86

Availability: In Stock
Speed Rating: WR
Performance Category: Ultra High Performance All-Season

In order to round out the g-Force T/A family, BFGoodrich wanted a tire that provided performance driving fun year round (even in snow) and developed the BFGoodrich g-Force T/A KDWS (Key benefits: Dry, Wet and Snow) to combine Ultra High Performance with All-Season traction. g-Force T/A tires are BFGoodrich’s flagship family of performance tires which includes everything from racing radials for the SCCA Trans Am Championship and DOT Legal Competition tires, to Max Performance and Ultra High Performance "summer" street tires.

The g-Force T/A KDWS uses a new tread compound molded into an asymmetric tread design with large, stable outer shoulder tread blocks to enhance dry traction while its inner independent tread blocks enhance wet road grip and light snow traction. Together, the tread compound and tread design help evacuate water from between the tire’s contact patch and the road to enhance wet grip when braking (it earns the highest "AA" UTQG Traction Rating) and cornering. Internally, the g-Force T/A KDWS’s polyester cord body incorporates BFGoodrich’s g-Control Sidewall inserts to enhance steering response and twin steel belts to deliver cornering stability. Additionally, the steel belts are reinforced with BFGoodrich’s ETEC (Equal Tension Containment System) spiral wound nylon to provide high speed durability while minimizing weight and maximizing ride qualities.

The g-Force T/A KDWS tires feature subtle black letter styling and are available in 55-, 50-, 45- and 40 -series; W-speed rated sizes for 16" to 17" wheel diameters.

[Black Terror]

All the Marauders I have seen have "Z" rated tires good for 149 MPH.

[Marauderman]

do they have a tire for 18" and rated for at least "Z"-149+--cause you
mentioned they have a "W" rated for 16 /17"--so for the 18's we have....???

[Black Terror]

BFGoodrich g-Force T/A KDWS - Size 245/55WR18
$86

[WolfeBros]

The Marauder brochure says W but what the heck.........it also said something about high performance oil pressure gauges......LOL :D

[TAF]

WR18 in the tire size spec means:

W speed rated
R radial
18 wheel size

Thats what I have on mine.

Unless I'm totally off-base. If I am, I'm sure someone here will point it out.

[Ken]

I don't know about the later cars, but just went outside and checked my stock tires and they are ZR 18's. Picked it up in June.:burnout:

[TAF]

And I appologize to Bill. You are right, I do have ZR 18s on mine. (Next time I'll use better light in the garage)

So...here's the question...are the WR18s on TireRack for $86 each a superior or different tire than the stockers? If so, even more reason to go ahead and buy/store at that price...you think? :bows: begging for forgiveness, Bill...

[TAF]

are the TireRack "W"s a better/different tire than the Stockers?

There's got to be some tire experts out there...

[SergntMac]

Gee, I don't know if a tire expert will have anything to add here. I'm supposin that we got tires (mine are Z, produced May, '02) that haven't been released to the public yet?

Lateral case in point, everything (yes, everything) sold at any Best Buy/Circut City, has to be 6 months behind current production, in order to keep the factory sponsored dealers supplied with stock, and given a fair playing ground for the retail market that shops by brand. After 6 months, the discount houses get the overstocks and leftovers for the discount only shoppers. My point here, is that TireRack, and others on the web, may be classified as a discount resellers, and not a retail brand POS. If so, TireRack (and likewise) would not have our factory stock Z rated tires, nor W, or Y rated tires in 18" for a while to come. Thinking about it deeper, what passenger car other than the MM calls for replacement of 18" tires right now? I see this in the wheel selections too, not much to pick from in dubz, that come in 18" or better, for a five bolt passenger car, you agree? Anyone check for a factory supported Goodrich retail dealer yet?

Just something to think about, IMHO...

[WolfeBros]

Just checked mine......ZR as well with a 6/02 build date.
The W in the tire number is what confused me.

Sarge you make a good point about the availability.

[TAF]

Sarge,

I don't see that TireRack is a overstock discounter. And they do have the exact tire listed in this spec from Mercury dated May '02 http://media.ford.com/article_display.cfm?article_id =11941
that specifies the same tire as I posted earlier above from TireRack which is available for $86.

Please don't misinterpret, I'm not complaining that I got "Z" rated tires instead of "W" rated tires (although that could be a question considering the info in the link above)....My question to hopefully someone here who knows more about tires than me (and that should not be too hard to find) is...Is there any difference (other than speed rating) of the WR18s compared to the ZR 18s which we have all identified that we have on our vehicles?

And....if there is no difference OR if they are better...I think that is an excellent price and I am probably going to buy and hold for the future.


Any opinions?

[Marauderman]

I understand what your saying!!! :D

[03 Merc]

Todd,

I would check the Traction and Treadwear rating to see if they are significantly changed... Treadwear may be lower... Load ratings may also be lower as well as speed rating climb.. It has been my personal experience that higher speed rated tires tend to wear faster than the equivalent lower ratings at least in Michelins.

When I do the wheel / tire change I am looking a H and V ratings as that is more than I'll need based on the top speed of even a DR modded MM... I need more of a load rating for my Class 3/4 anyway..;)

[CJOHNSON]

Does anyone know what the treadwear rating is on the supplied tires?

[TAF]

And I understand you needs with the towing. I appreciate the response.

And Tom...you and I are "reading from the same sheet of music" - Sir...

[03 Merc]

CJohnson,

It's stamped on the sidewall of your tires.. I would look but is it's too darn cold here!!

[CJOHNSON]

Thanks for the reply Wayne. I am trying to roughly figure out how often I will have to buy tires if I put 20,000 miles per year on the car with normal driving conditions. With quotes of $520 to $700 per set of tires I wanted to be sure to allow for a monthly tire budget in my family finances when I buy the car.

Charles

[LincMercLover]

Exactly where is this WR/ZR printed on the tire? I have yet to see this...

I've always heard Z rated mean you can do 200MPH on them. Now charts will show 149+MPH, equivalent to that of a Y I believe... Now if tirerack.com has W's, then that means they have a 169MPH top speed rating. So if the 200MPH thing is correct, our stockers are better than Tire Racks'. But who's gunna do 200MPH besides mesrea? :D

PS: Did anyone read their BF Goodrich packet? No burnouts with over 35MPH wheel spin, or :po: !

[FordNut]

I just got a set from tire rack and found that they are exactly the same Z speed rating as the ones on my car. Don't know why tire rack lists them as a W speed rating. No, mine aren't worn out yet, I'm working on a special project.

[martyo]

Originally posted by FordNut
No, mine aren't worn out yet, I'm working on a special project.

Stop being a tease......

[TAF]

Marty...you're just jealous...'cause his sig makes yours look like a "stocker" :lol:

[mdmarauder]

I Figured that the Tire Rack had the same exact tire we have. They are awesome when it comes to wide or low-profile tires. My dealer wants around $250.00 a tire.