Bolt pattern | stud pattern

Speed Rating

How to Read Speed Rating of a tire? 


Speed rating is determined by tests condacted by tire manufactures where the tire is pressed against a large diameter metal drum to reflect its appropriate load. Even though Manufactures speed rating may be higher , but  it usually does not mean that a vehicle is recommended to overpass the speed limit of the highway.

Its very important to know that Speed rating is only valid if a tire is in a healthy condition. It means that the tire must not been damaged, altered, under-inflated or overloaded. Even though a tire might have been fixed, its still very hard to determine how well it has been fixed . That’s why speed rating does not apply to tires that have been fixed as well.


Speed Rating

Speed Rating


The letter symbolises the SPEED RATING can be seen in three different ways .

205/55SR16  —–> This type of branding was used on tires prior to 1991

205/55SR16 89S

205/55R16 89S

Its recommended that the SPEED RATING on all tires of your vehicle should be the same.

Mixing different speed rating may cause some mechanical problems in the long run.

Speed  Rating Chart

L 75 mph 120 km/h Off-Road & Light Truck Tires
M 81 mph 130 km/h
N 87 mph 140km/h Temporary Spare Tires
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars
W 168 mph 270 km/h Exotic Sports Cars
Z Over 149 mph 240 km/h Same as (V) Rating, After the tire manufactures made tires with a speed rating of over 149mph , they are using the symbol Y and W instead of Z which meant Speed rating of over 149 mph.


At , you will fine lots of info about your wheels , rims .
You will fine bolt pattern. you will find stud pattern. you will find information about the wheels and rims on your car.
you can also find the information about your lug nuts, CB ( Center Bore ) or Center hole and offset of your rim. Most rims are interchangeable from one car to another car.
To find out you need to compare your bolt pattern with the bolt pattern of the wheel you have on hand. Sometimes its difficult to find out about the specific information about the rims if you only have the wheels but no stud or bold pattern information . i used to take my rim to a junk yard and try one on a different wheel hub with off course with calipers on the rims. Then i recorded the make, model and year of the car and was looking for the wheel information about that rims. That way i was finding my car's bold pattern. Now I am quite used to recognizing the stud pattern. Its my eyes that do the magic. i can easily tell if a rim will fit a car or not.
Its a couple factor that really decide if a rim will fit into a car.

Bold pattern | Stud pattern :
Used to describe the amount of lugs your car, or wheels, have, and also the measurement in between them.
For example, 5x4.5 This would be 5 lugs, spaced 4.5" across.
Also measure in mm, for example 5x114.3. 5 lugs, spaced 114.3 mm apart. 5x4.5 = 5x114.3

CB (Center Bore or Center Hole ) :
The centerbore of a wheel is the size of the hole in the back of the wheel that centers it over the mounting hub of the car.
Some factory wheels have a centerbore that matches exactly with the hub to reduce vibration by keeping the wheel centered. Wheels with the correct centerbore to the car they will be mounted on are known as hubcentric. Hubcentric wheels take the stress off the lug nuts, reducing the job of the lug nuts to center the wheel to the car.
Wheels that are not hubcentric are known as lugcentric, as the job of centering is done by the lug nuts assuming they are properly torqued down. Centerbore on aftermarket wheels must be equal to or greater than that of the hub, otherwise the wheel cannot be mounted on the car.
Many aftermarket wheels come with "hubcentric rings" that lock or slide into the back of the wheel to adapt a wheel with a larger centerbore to a smaller hub.[3] These adapters are usually made of plastic but also in aluminum. (Courtesy of Wikipedia)

Offset :
Offset is the measurement of where the mounting surface of the wheel is (where the bolt holes are), compared to the centerline of the wheel. Usually referred to as negative, positive, or zero offset or Low, Medium or High. other property of the wheels are also effective in deciding to purchase a rim for your car but basically i found the above properties most important.
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