thankfully, determining the correct tire size for your vehicle is relatively simple. All the information you need is immediately available either in your owner ‘s manual of arms or somewhere on the vehicle itself. already know how to read run down size numbers ? Skip the explanation and find the right Bridgestone tire for your vehicle on-line or by visiting a Bridgestone run down principal near you.
While actual, physical measurements like width and diameter are factors in finding the right bore size, there are extra details to consider. Knowing how to read car tire sizes besides means reason terms like load index and travel rapidly rate that affect your fomite ‘s overall capabilities.
Reading: How to Read Tire Size
WHERE TO FIND A CAR TIRE SIZE
No matter what vehicle you drive, finding the manufacturer-recommended run down size should be easy. The best place to start looking is the owner ‘s manual .
Do n’t worry if you ca n’t locate the manual ; you may besides find a run down fit guide in these locations :
- The driver’s side door jamb
- Inside your glove box door
- Within your gas tank hatch
You can besides find bore size data on the sidewall of your stream tires ( assuming they ‘re the proper size ). however, no topic where you find your tire size, you will have to decipher a sequence of numbers and letters. Do n’t worry if it looks confusing at first — every letter and number has a aboveboard mean. Let ‘s break down how to read car run down size .
HOW TO READ TIRE SIZE
Let ‘s take a spirit at what each numeral or letter stands for, one by one, in the holy order they appear in your tire size data. We ‘ll be using this tire size as an exercise : P225/70R16 91S .
THE LETTERS “P” AND “LT”
For most vehicles, you ‘ll see the letter “ P ” before the count sequence begins : P225/70R16 91S. The “ P ” is abruptly for “ P-metric, ” which is a appellation by the Tire and Rim Association for a “ passenger cable car ” bore type. A “ P ” signifies the bore was designed to primarily be used on passenger vehicles, which can include cars, minivans, SUV ‘s and other light-duty pickup trucks .
If you see “ LT ” rather of “ P, ” it ‘s because you need “ light hand truck ” tires – “ LT ” is short-circuit for “ LT-metric, ” which is a appointment by the Tire and Rim Association for a “ light up truck ” type bore. lighter truck tires are designed to be used on vehicles capable of carrying heavy cargo or pulling trailers .
similarly, “ T ” stands for “ irregular ” and is for your spare tire. If you see “ ST, ” that means “ special trailer. ” A particular dawdler tire is never installed on the repel or steer wheels. It ‘s only intended for use on trailer axles .
WIDTH
The first count to appear in your tire size information is the width, in millimeters, of the discipline tires for your vehicle : P225/70R16 91S .
Tire width always refers to the measurement from one sidewall to another. therefore, a tire with the measurement “ P225 ” is for a passenger vehicle and has a nominal width of 225 millimeters .
ASPECT RATIO
After the convulse mark, the next numeral you see is for the tire ‘s aspect ratio, which basically tells you how tall your run down ‘s profile is : P225/70R16 91S. aspect ratios are delivered in percentages. run down makers calculate the aspect ratio by dividing a run down ‘s sidewall altitude by its width. If a tire has an aspect proportion of 70, it means the tire ‘s height is 70 % of its width .
Lower aspect ratio tires, such as a 60 series, by and large offer vehicle handling performance advantages over higher view proportion tires, such as a 75 series .
CONSTRUCTION
After the expression proportion comes a letter to indicate the tire ‘s construction : P225/70R16 91S. “ R ” refers to the home structure of your tire and gives you a general estimate of its constancy .
There are two types of construction that you may see on the sidewall of a tire
- R – Radial
- D – Diagonal or Bias Ply
“ Bias-ply ” tires were used on automobiles and inner light trucks until the ’70s, ” reports the authoritative car web site, Hemmings. But radial tires represent the huge majority of tires on the road in the United States today. In fact, you will about always see the letter “ R ” on tires as radial tires have been the diligence standard for over 40 years. radial construction means the run down ‘s inner ply cords are oriented in a radial guidance ( at 90 degrees to the centerline of the tread ) .
RIM DIAMETER
The following number is the roulette wheel ’ mho diameter. For model, a tire with the P225/70R16 91S would fit a rim with a 16-inch diameter .
Take note : if you decide to change your rims ‘ size, you will besides need to get new tires that are compatible with the change in size. Tires designed to fit a 16-inch steering wheel diameter will not stretch to fit on newly 18-inch rims .
view other Common Diameter Sizes :
14-Inch Diameter Tires
15-Inch Diameter Tires
17-Inch Diameter Tires
18-Inch Diameter Tires
19-Inch Diameter Tires
20-Inch Diameter Tires
21-Inch Diameter Tires
22-Inch Diameter Tires
LOAD INDEX
The future human body needed to read tire size numbers is your run down ‘s load index. The warhead index tells us how much burden, in pounds, the tire can support when fully inflated : P225/70R16 91S .
It is called the load “ index ” because the name does n’t tell us the precise number of pounds the bore can support, at least not by itself. rather, the number corresponds to a specific load capacity listed in an index. Beginning with one and ending with 150, numbers in the load exponent present carrying capacities of 99 to 7385 pound .
additionally, you may not find this number give on all tires. This is because the lode index is not required by law to be printed on tires. If there is no burden index measurement on your tires, check the owner ‘s manual or contact your local anesthetic Bridgestone tire dealer for more information .
SPEED RATING
The concluding figure in a run down size sequence is the amphetamine rate indicated by a letter : P225/70R16 91S. barely as your load index act corresponds to a especial load, your speed evaluation letter corresponds to a specific amphetamine capability based on a standardize testing ground quiz .
For example, a run down with a speed rate “ S ” is rated for up to 112 miles per hour, while a tire rated “ R ” is up to 106 miles per hour. Remember that this is n’t a commend cruise speed, but rather the utmost speed that tire type can withstand. Of naturally, you should constantly follow legal accelerate limits on roadways .
here are the most common letters for speed ratings and their corresponding maximal speeds :
- Q: 99 mph
- R: 106 mph
- S: 112 mph
- T: 118 mph
- U: 124 mph
- H: 130 mph
- V: 149 mph
- W: 168 mph
- Y: 186 mph
- ZR: 186+ mph
Tires with higher travel rapidly ratings tend to offer increased wield performance. refilling tires must have the same or higher accelerate evaluation to maintain vehicle speed capability. If a vehicle has tires with different speed ratings, the speed rat of the “ slowest ” tire dictates the vehicle ‘s top speed .
Like the load index, the rush rat is not required by police to be listed on all tires. If your tires do not have the rush rat listed, your owner ‘s manual will have the relevant information for your model ‘s standard tire type .
SEVERE SNOW CONDITIONS
You may find “ M+S ” or “ M/S ” after the main run down size succession on some tires. This indicates that the tire has some capability to handle snow and mud conditions. This indication is coarse on most radial or “ R ” type tires .
USDOT TIRE IDENTIFICATION NUMBER
You may notice another determine of letters and numbers on your tire ‘s sidewall beginning with “ DOT. ” This is not an reading of run down size, but rather that the tire complies with Federal Motor Vehicle Safety Standards. The “ DOT ” stands for Department of Transportation and is followed by the bore identification number.
The first two letters or numbers after DOT mention to the fabricate plant where the tire was produced and the end four numbers indicate the workweek and year the run down was made. The numbers 4318, for example, indicate that the tire was manufactured during the 43rd week of 2018 .
CAN I PUT LARGER TIRES ON MY CAR?
While it ‘s surely possible to upgrade your tires ‘ size, it ‘s normally best to stick to your manufacturer-recommended run down size for optimum performance. Increasing the size of your tires may give your car more grind clearance, but it may besides affect treatment, drivetrain performance and fuel economy. Keep in mind the changes to key figures mentioned above, such as load index and travel rapidly fink, and how they may affect your fomite ‘s capabilities if you decide to increase tire size .
SHOP TIRES BY SIZE
once you know how to read the numbers on tires, you can explore tires by size and narrow down your tire options promptly. Compare tire sizes online or visit a Bridgestone tire dealer near you for help .
