What do the three sets of numbers on tire size?
Tire width/section width/cross section are the first three tire numbers of the code, in millimeters. The measurement shows the distance from the widest spot of the inner sidewall to the same of the outer sidewall. Tire width can vary depending on the rim, so tire engineers mount the items on specified rims while calculating.
What does the middle number mean on tires?
the middle number is the profile of the tires. so yea, your 16 inch tires WERE bigger, but since you put on larger rims, it's likely they put on tires with a lower profile to keep the overall wheel diameter the same (which they do for safety reasons).
What do the numbers in the tire size relate to?
Here's what the letters and numbers on your tires mean. The most basic information that you'll find on a tire's sidewall is related to its size. This is normally written as 185/65R15, for example, though you'll sometimes see "P" (for passenger cars ...
What do the numbers stand for on tire sizes?
What Do Tire Numbers Mean? The letters and tire numbers printed on the tire represent model, width, aspect ratio, construction, wheel diameter, load index, and speed rating. For a better understanding, let’s take the series “P215/65R15 95H” as a reference. Type
What is the difference between 50 and 55 on tires?
The 50 (or 55) is the height of the sidewall, as a percentage of the width. That's your aspect ratio. With a 55 aspect ratio, and a 225 treadwidth, you'll end up with a tire that is 3/4 of an inch taller that the 225/50.
Is the middle number on a tire the width?
B: TIRE WIDTH The three-digit number following the letter is the tire's width (from side to side, looking at the tire head on) in millimeters. This may also be referred to as the section width.
What does the 265 70R17 mean?
How to read your tire size long description. An arrow points to the numbers 265/70R17 115T on the inner part of the tire sidewall. 265 is the width, 70 is the aspect ratio, R stands for radial, 17 is the wheel diameter and 115T is the load index and speed symbol.
What are the 3 tire size numbers?
Tire Size Meanings. The three numbers you will find on the tire's sidewall represent the width, the height, and the diameter of the tire, respectively. The width is measured in millimeters and indicates how wide the tire is from side to side. The height is measured in a height-to-width ratio.
Does the middle number on tires matter?
The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tire's width. The bigger the aspect ratio, the bigger the tire's sidewall will be.
Can you change the middle number on tires?
That said, the only dimensions you can change are the width and aspect ratio — never the wheel size, unless you buy replacement wheels — and you should always strive to keep the total height of the tire the same as the OEM. So, if you widen the tire, you may need to decrease the aspect ratio, and vice versa.
What is the difference between 265 70R17 and 265 65R17?
The 265/70R17 is a General Grabber ATX and the 265/65R17 is the stock Hankook. And just for fun, it doesn't look very big compared to a 26x4. 8” bike tire, it's just barely taller!
How tall is a 285 tire?
The sidewall height or "aspect ratio" of a 285/75/R16 tire is 75% of 285mm. Example: 285/75R16 (285 X 75 / 2540 x 2) + 16 = 32.8 inches tall.
What is the difference between a 265 tire and a 245 tire?
The 245 and 265 represent the width of the tire in millimeters. The main difference between 245 and 265 tires is the width. The 265 tire is wider at 10.43 inches, while the 245 tire converts to 9.65 inches.
Can I use 245 tires instead of 235?
The quick answer is yes you can replace 245/50-18 tyres with 235/50-18 but they will have 10mm (0.4 in) smaller overall diameter. Will only slightly effect speedo and odometer - ie speedo will read about 1.5% high.
How do I read tire size?
The first number to appear in your tire size information is the width, in millimeters, of the correct tires for your vehicle: P225/70R16 91S. Tire width always refers to the measurement from one sidewall to another.
What does 275 mean on a tire?
The numbers in the tire size refer to its width, aspect ratio, and wheel diameter. "275/35R19" means the tire is 275 mm wide, has an aspect ratio (that is, the width divided by the height) of 35%, and fits on a 19" wheel.
How do you tell the width of a tire?
Width. The first number to appear in your tire size information is the width, in millimeters, of the correct tires for your vehicle: P225/70R16 91S. Tire width always refers to the measurement from one sidewall to another.
What does 96t on a tire mean?
So, what does the T or H mean on tires? The “T” or “H” on tires pertain to their speed ratings. A T-rated tire can withstand top speeds of up to 118 mph (190 km/h), while an H-rated tire can support up to 130 mph (210 km/h). It is important to note these markings and stay within those speed limits.
How wide is a 275 tire?
275/70R17 tires have a diameter of 32.2", a section width of 10.8", and a wheel diameter of 17". The circumference is 101.0" and they have 627 revolutions per mile. Generally they are approved to be mounted on 7-8.5" wide wheels.
How wide is a 225 tire?
The number “225” stands for the width of the tire in millimeters – so in this case the tire is 22.5 cm wide. The “45” that follows is the aspect ratio - the height of the tire sidewall as a percentage of its width.
What is the number on a tire?
B: TIRE WIDTH The three- digit number following the letter is the tire’s width (from side to side, looking at the tire head on) in millimeters. This may also be referred to as the section width.
What is tire size calculator?
A tire size calculator is a quick way to see whether the tire size you’re considering will likely fit your car, SUV, sports car, light truck or crossover.
What does the first letter in the tire code tell you?
A: TIRE TYPE The first letter in the code tells you what class of tire it is .
What does it mean when a tire has a higher speed rating?
A tire with a higher speed rating can handle heat better and provide more control at faster speeds. The maximum operating speed of a vehicle is no more than the lowest speed rating of all tires mounted on the vehicle.
What is a metric tire?
If there’s no letter before the first number, you have a metric tire most commonly referred to as European size. It’s also measured in millimeters but may have a different load capacity than a P or LT tire.
What is the aspect ratio of a tire?
The aspect ratio is indicated on the tire sidewall as a percentage. It’s the height of the sidewall measured from wheel rim to top of the tread, expressed as a percentage of tire width.
What is a radial tire?
In a radial tire, the plies — layers of strong cords made of a blend of polyester, steel and fabric and coated with rubber — are laid perpendicular to the direction of travel. D is for tires built with diagonal (crisscrossed) plies, called bias-constructed tires. They are also called conventional, x-ply, or cross-ply tires.
What is the width of a tire?
Tire width always refers to the measurement from one sidewall to another. Thus, a tire with the measurement "P225" is for a passenger vehicle and has a nominal width of 225 millimeters.
What does M+S mean on tires?
You may find "M+S" or "M/S" after the main tire size sequence on some tires. This indicates that the tire has some capacity to handle snow and mud conditions. This indication is common on most radial or "R" type tires.
Why isn't load index on tires?
Additionally, you may not find this number present on all tires. This is because the load index is not required by law to be printed on tires. If there is no load index measurement on your tires, check the owner's manual or contact your local Bridgestone tire dealer for more information.
What size tire fits a 91S rim?
The next number is the wheel’s diameter. For example, a tire with the P225/70R16 91S would fit a rim with a 16-inch diameter.
What is load index?
It is called the load "index" because the figure doesn't tell us the precise number of pounds the tire can support, at least not by itself. Instead, the number corresponds to a specific load capacity listed in an index. Beginning with one and ending with 150, numbers in the load index represent carrying capacities of 99 to 7385 lbs.
Why do tires have higher speed ratings?
Tires with higher speed ratings tend to offer increased handling performance. Replacement tires must have the same or higher speed rating to maintain vehicle speed capability. If a vehicle has tires with different speed ratings, the speed rating of the "slowest" tire dictates the vehicle's top speed.
Why is it important to install tires?
Installing the right tires on your vehicle is essential to the overall performance and safety of your vehicle. Your tire choice should reflect the conditions in which you drive and your preferences for vehicle response and handling. To make the most informed decision, though, you must understand how to read tire size when it's time to buy tires.
What does 65 mean in a tire?
In this example, the aspect ratio number “65” means that the tire’s height is 65 percent of its width.
What is a D tire?
The other letter you might see here is a “D,” which denotes a tire that has a diagonalor bias plyconstruction.
What does 65 R15 mean?
The “R” in this sequence refers to the construction of this tire. Specifically, the “R” means that the layers run radially across the tire.
Do you need fancy tools to replace tires?
Wondering when to replace tires? You don't need any fancy tools. Learn how to check tire tread depth with the tire penny test, with help from the pros at Firestone Complete Auto Care. It's quick, easy, and one of the best ways to ensure your safety on the road.
How to read tire size?
There are two ways that tire manufacturers display tire size, inches and metric. How to read tire size in inches is very straight forward. Example A : 33X12.50R15 The first number is your overall diameter of the tire. In this example the tire diameter or "height" is 33 inches tall. The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example "A" this reads 12.50, meaning the tire width is 12 and 1/2 inches. The final number simply is the wheel size or "diameter" of the wheel that the tire will fit on.
What is the final number of a tire?
The final number simply is the wheel size or "diameter" of the wheel that the tire will fit on. How to read tire size with a metric measurement is a little more difficult and usually takes a calculator to get exactly right.
What does the second number mean on a tire?
The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example "A" this reads 12.50, meaning the tire width is 12 and 1/2 inches.
What is a LT tire?
The tire is designed to be mounted on an 15 inch wheel diameter. Tire Class : LT. The tire class of this tire size is 'LT' which means it is a Light Truck tire.
How to convert 285mm to inches?
To convert 285mm to inches you divide 285 by 25.4 to get 11.22". So the width of a 285mm tire is 11.22". The next number represents the percentage of the width (285mm or 11.22") that is the sidewall height of the tire. In this example the side wall height of the tire would be 75% of 11.22" which is 8.41" or 214mm.
What does R mean on a tire?
R — This indicates your tire's design, which in this case is radial. Radial is the most common tire design on the market today, but you might see one of these instead:
What does load index mean on a tire?
Load index is a code that indicates how many pounds a tire can carry at a given inflation level. In this instance, a load index of 92 would mean that tire is capable of carrying 1,389 pounds at 36 psi inflation. H — This indicates the speed rating. Speed rating is the highest speed a tire can safely handle, determined through lab testing.
What is the aspect ratio of a sidewall?
65 — This two-digit number is the aspect ratio. Aspect is the height of the sidewall expressed as a percentage of the section width; in this case, the sidewall's height is 65 percent the width of the section width.
What is 520 tread?
The treadwear grade is on a scale compared to other tires, and the 520 figure places this tire on a scale. Treadwear grades were designed by the National Highway Safety Administration and take heat resistance, rolling resistance, and other factors into account, and a tire with a treadwear grade of 200 is rated with twice the tread life of one with a 100 grade. Although this is part of the Uniform Tire Quality Grade, you're better off referring to your tires' actual treadwear warranty.
What is a LT tire?
LT is for a light truck. ST is for a special trailer. T is for temporary, usually indicating a spare tire. European-standard tires won't have a prefix letter at all. 205 — This is the section width of the tread, from sidewall to sidewall. In this case, the tire's section width is 205 millimeters.
What is the maximum speed of a tire?
Speed rating is the highest speed a tire can safely handle, determined through lab testing. In this case, an H-rated tire is good for speeds up to 130 mph. Code. Maximum Speed (mph) Q. 100.
Can you tell if a tire is a tire?
Your tires can tell you a lot — if you know how to read what they have to say. Many years ago, the tire industry established a set of standards for the information that's embossed on the sidewall of tires.
What is the width of a tire?
The width of the tire can vary from 125 mm to 335 mm. The width always goes in steps of 10 mm. Tire sizes range from 125-135-145-155-165-175-185-195-205-215-225-235, etc. The tire width of the average middle class car is 205 mm wide.
What are the factors that determine tire size?
The tire size is made up of 7 factors, namely the width of the tire, the height of the tire, the type of tire, the rim size, and the load capacity and speed index. Tire Size Chart: Tire Dimensions explained.
How to calculate tire height?
Height of car tire In the tire size, the number that comes after the width of the tire (2nd part) is the height of the tire which is a percentage of the width of the tire. In the example above that number is 55. This means that the height of the tire is 55% of the width of the tire, which in this example is 195 mm. The calculation is easy by multiplying the width of the tire (195) by 0.55. You then arrive at 107.25 mm
What is the direction of rotation of a tire?
The direction of tire rotation: What is independent of the tire size is the direction of rotation. Some tires have an arrow on the side of the tire. This arrow indicates the direction of rotation / running direction of the tire. The arrow must always point towards the front of the car. Tires with a V profile have at least an arrow and therefore also a running direction. Pay attention to this when mounting the tire or when changing a wheel. The steering and driving behavior can be directly influenced by incorrect mounting.
What is rim size?
The rim size is the size of the rim around which the tire fits exactly. This is the inner size of the car tire and the outer size of the rim. Rim size is almost always given in inches.
What does R stand for in tires?
The tire type is in almost all cases indicated with the letter R. R stands for Radial . Radial explains how the tire was made. With a Radial tire, steel cord plies are applied perpendicular to the direction of rotation, so in the width of the tire. This makes the tire very flexible and maintains contact with the road surface when cornering. The counterpart of the Radial tire is the Diagonal tire. With the Diagonal band, the cord layers are placed diagonally over the band.
Why are rims bigger?
A larger rim fits wider tires which are necessary for better road holding and can also handle a higher weight. Nowadays, cars are increasingly equipped with larger rims (15 ″ / 16 ″ / 17 “) because this is not only more beautiful and sporty, but also because the tires are more common, which makes them cheaper.
How to read metric tires?
Inch measurement tires are fairly easy to understand however metric tires use a more difficult system to read. The first number on a metric tire is the width in millimeters. Divide this number by 25.4 to get the inch equivalent as there is 25.4 mm in 1 inch.
What is the third number on a tire?
The third number generally preceded by an "R" is the wheel diameter . The sidewall or aspect ratio are used in metric tire sizes to determine the overall height of a tire. The second number on a metric tire is to calculate the side wall measurement. The sidewall height is a percentage of the width of the tire. This second number is that percent.
What does a speedometer tell you?
A speedometer reads the amount of revolutions your tires are making, not how far you are traveling. Therefore you are actually traveling faster than your speedometer says when you have larger tires than stock, and slower than you're speedometer says if you have smaller tires.
