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Discussion Starter · #1 ·
I picked up my Z last week. The tire rating on the Potenza's is "R." An R rating for a car capable of 150+ mph? Does anyone have an answer for this?

(btw, I just bought some new rims with Toyo's rated at "W.") :cheers:
 

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That is not the speed rating. In fact there is no speed rating of R. :

The "R" stands for Radial, meaning it has a radial construction. Radial tires have ply cords that extend to the beads and are laid at 90 degrees to the centerline of the tread, the carcass being stabilized by a circumferential belt.


Here are the speed ratings:
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
 

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Discussion Starter · #3 ·
Originally posted by TOYKILLA@Aug 16 2005, 05:15 PM
That is not the speed rating. In fact there is no speed rating of R. :

The "R" stands for Radial, meaning it has a radial construction. Radial tires have ply cords that extend to the beads and are laid at 90 degrees to the centerline of the tread, the carcass being stabilized by a circumferential belt.


Here are the speed ratings:
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

[snapback]146256[/snapback]​



My point, exactly. How could Nissan put these tires on this car? Even my Mustang came with Z's.
 

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So if we have Ws, and Mustangs have Zs, why are you upset that our tires can handle faster speeds?
 

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Discussion Starter · #8 ·
Originally posted by TOYKILLA@Aug 16 2005, 08:14 PM
I tested the W speeds.. the tires held up :thumbsup:
[snapback]146296[/snapback]​



W? Then why do my OEM tires say R? Instead of WR? I'll let you know as soon as my Toyos & rims get delievered. I think it may be class action suit time. I'll do some research on the Bridgestones. Stay tuned.
 

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Discussion Starter · #10 ·
Originally posted by RUFDRAFT+Aug 16 2005, 09:08 PM-->
<!--QuoteBegin-TOYKILLA
@Aug 16 2005, 08:14 PM
I tested the W speeds.. the tires held up :thumbsup:
[snapback]146296[/snapback]​



W? Then why do my OEM tires say R? Instead of WR? I'll let you know as soon as my Toyos & rims get delievered. I think it may be class action suit time. I'll do some research on the Bridgestones. Stay tuned.
[snapback]146305[/snapback]​


Well, I checked, and our OEM's are, in fact, W rated. I can't understand why they don't have that marking on the tire. Sorry for starting this before I did my homework. :banghead: (I should know better...)
 

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Discussion Starter · #12 ·
Originally posted by Jetpilot718@Aug 16 2005, 09:19 PM
To make sure theres no more confusion:

245 40 R 18 --- means 245 (width) 40 (profile) R (radial) 18 (rim diameter)
[snapback]146320[/snapback]​


I was only confused by the lack of a speed rating - not the tire dimensions.
 

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The Potenzas have '96W' written on the sidewall. The number is defined as:

"A service description identifies the tire's load index and speed rating. It can be found on the sidewall of the tire after the size listing.

The load index is the tire size's assigned numerical value used to compare relative load carrying capabilities. The speed rating is a letter denoting a fixed maximum speed capability."
 
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