Tire Size Meanings
- Tire Type. Most car tires have the letter “P” at the front of the tire size. ...
- Tire Width. The tire is measured by its width. ...
- Aspect Ratio. After the slash mark, the next number you will see is the tire’s aspect ratio. ...
- Construction. Most passenger tires feature an “R” after the aspect ratio. ...
- Wheel Diameter. ...
- Load Index. ...
- Speed Rating. ...
- DOT Symbol. ...
- TIN. ...
- UTQG. ...
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 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.
How tall is a 285 tire?
What does the 285 mean in tire size? This represents the treadwidth of the tire. The tread is 285mm wide, or 32.587 inches wide. What does the 65 mean in tire size? This represents the sidewall height of the tire, as a percentage of the width. The sidewall height is 65% of 285mm, or 185.25mm, which is 7.293 inches.
What do the 3 numbers on tire size mean?
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. C: ASPECT RATIO The forward slash separates the tire width number from the two-digit aspect ratio.
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 do all the tire numbers mean?
The first number measures the width and it looks something like this: [205/65 R 15]. The 205 on the tire means it is 205 millimeters wide looking at the tire head on. The second number, 65, is the aspect ratio, which means that the height of the tire is 65% of the tire's width for this example.
How do you read the numbers on a tire size?
The first number is the load index if the tire is used in a single application, the second number is the load index if the tire is used in a dual application. Passenger type tires cannot be used in a dual application. Light truck tires will also have a Load Range that is indicated by a letter, such as Load Range E.
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.
Can I use 205 60r16 instead of 205 55r16?
Yes. It will have a slightly lower sidewall height, but should work fine.
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.
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 285 tire?
285/75R18 tires have a diameter of 34.8", a section width of 11.2", and a wheel diameter of 18". The circumference is 109.4" and they have 579 revolutions per mile. Generally they are approved to be mounted on 7.5-9.5" wide wheels.
Can I use 175 tires instead of 185?
That is the size you would ideally want to stay with. Both a 175/80-13 and 185/80-13 will fit the same size wheels (4-1/2 to 5-1/2 inch wide) and they are about the same diameter (between 24 and 24-1/2 inches). The major difference is the capacity. A 175 tops out at 1,610 pounds for a load range D, # AM10210.
Can I put a different tire size on my car?
Wheels and tires are not interchangeable words. Tires are a part of the wheel setup. For instance, your vehicle has a set size of rims, but you can buy different sizes of tires to fit those rims, as long as the middle of the tires is the correct size.
What is the 265 on a tire mean?
265 = Section Width in millimeters (measured at the widest part of the tire from sidewall to sidewall) /60 = Aspect Ratio or section height to width ratio as a percentage. For this example, the side wall is 60% of the section width of the tire (265mm x . 60 = 159mm). Therefore, the sidewall height is 159mm.
What size is a 265 70R17?
265/70R17 tires are 31.6″ tall, have a section width of 10.4″, and fit wheels with a diameter of 17. The circumference is 99.2″ that translates into 638 revolutions per mile. As a rule, they can be mounted on the wheels with 17″ x 7-9″(LT Tires 7-8.5″) rim width.
What is the difference between 225 and 265 tires?
Registered. Not quite that simple,, 225 and 265 are the width, but 75 or 70 is an aspect ratio of the width to the sidewall so a 225/75/16 is 29in tall, a 265/75/16 will be 31.5in tall, and 265/70/16 will be 30.5in tall. (width divide by 25.4 times aspect ratio divide by 100, times 2 plus rim diameter).
What is the meaning of 265 65R17?
265/65R17 tire has a sidewall height of 6.8 inches or 172 mm which is the measurement of tire sidewall from the wheel rim to the top of tire tread. Tire sidewall height or "profile" depends on aspect ratio - lower aspect ratio means lower tire profile.
What are the sizes of tires?
Tires usually come in the following widths (in inches): 8, 10, 12, 13, 14, 15, 17, 18, 19, 20, 22, 23, 24, 26, and 28. Tires in these sizes are typically found on most passenger cars, light-duty light trucks, SUVs, minivans, and vans. Tires with a rim diameter measured in inches are called "inch rim" sizes.
What does the 2 digit number on a tire tell you?
The two-digit number that usually follows the tire's section width tells us the aspect ratio, or tire profile measurement.
What is a metric tire?
Metric tires, also known as Euro-Metric tires because the sizing originated in Europe, don't have a letter designation. Euro-Metric sizes are equivalent to P-Metric sizes in dimensions, but Euro-Metric sizes have subtle differences in their load-carrying ratings and capabilities. Euro-Metric tires are usually found on European cars, but they're also used frequently used on SUVs and vans.
What is a P tire?
P-Metric tires are the most common type of tire. The P stands for passenger vehicle, meaning that these tires are designed for use on passenger vehicles like cars, minivans, light-duty pickup trucks (? ton or ? ton capacity), and SUVs.
How wide is a tire?
In the example above, the tires width, measured from the widest point of the inner sidewall to the widest point of the outer sidewall when properly mounted, is 225 millimeters. The section width can be converted to inches by dividing the width in millimeters by 25.4 like so: (225 millimeters) / (25.4 mm/in) = 8.86 inches.
What size tires are used for heavy cargo?
Wide base tires are also designed to carry heavy cargo loads and/or tow trailers on a wheel rim with a diameter of 16.5 inches.
What does a T mean on a tire?
If the tire size begins with a T, it means that the tire is a temporary spare. Also known as mini spares or space savers, temporary spares are designed for short-term use until the regular tire is repaired or replaced.
What does tire size mean?
Tire Size Meaning. There are two ways that tire manufacturers display tire size, inches and metric. To find the tire size meaning in inches is very straight forward. The first number is your overall diameter of the tire. In this example the tire diameter or "height" is 33 inches tall.
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. The final number simply is the wheel size or "diameter"of the wheel that the tire will fit on.
How to find tire height?
To get the overall diameter or "height" of the tire you would add the two sidewalls and the diameter of the wheel. In example "B" the last number "17" is the wheel size the tire will fit on. Therefore the sidewall twice would be 8.41 x 2 = 16.82 plus the wheel "17" makes the tire height 16.82 + 17 = 33.82.
How many inches is 305mm?
There are 25.4 mm in one inch. To convert 305mm to inches you divide 305mm by 25.4 to get 12". So your width of a 305mm tire is 12 inches. The next number represents the percentage of the width (305mm or 12") that is the sidewall measurement of the tire.
What is the tire number on a tire?
Tire numbers and letters on a sidewall contain information about the tire’s size, maximum speed and load, age, treadwear capacity, and much more. You can learn all these details from three main codes: size code, Department of Transportation (DOT) code, and Uniform Tire Quality Grading (UTQG). There are also additional symbols that represent special features and capacities of the tire.
What are the dimensions of tires?
The following tire numbers represent rim/wheel diameter (measured from one side to another). The two-digit number is in inches and the most regular sizes are the following: 8”, 10”, 12”, 13”, 14”, 15”, 17”, 18”, 19”, 20”, 22”, 23”, 24”, 26”, 28”. You can see such tires on most passenger vehicles. There are also tires with irregular rim diameters that are often used for box vans, heavy-duty light trucks and trailers. The tire numbers include: 14.5”, 14.5”, 16.5”, 16.5”, 19.5”. Such tires are for specific use and not to be mixed with regular tires. Additionally, some tires use rim diameters in millimeters, but these are rare. Michelin PAX run-flat tires, which are limited Original Equipment (OE) tires in the US, use this system.
How much does 91 tire index mean?
So, if you want to learn the load capacity of the whole set, multiply the mass by 4. So, according to the table, 91 index means 1,356 pounds per tire , or 5,424 per set.
What is the tire profile of 55?
So, 55 profile is 55% of the width, meaning the tire’s height is (taking the width of 205 mm) 112.75 mm or 4.4”. You may see tires without these tire numbers, meaning the tire’s profile is standard – 82%. Also, there are rarely tires with the ratio of three digits, which means it’s in millimeters.
What is LT tire?
LT – the tire is for light trucks (some SUVs, medium and heavy duty pickups of ¾-1 ton load capacities). ST – the tire is a special trailer tire used on utility, car, and boat trailers. T – the tire is temporary (spare). These are the tires that can be used until the repair or replacement of the main tire is done.
What does the letter F after R mean on a tire?
This means the tire has self-supporting run-flat construction adopted by the European Tyre and Rim Technical Organization (ETRTO).
How many digits are in a tire plant?
Plant code. Every legal tire plant in the world should have a two- or three-digit, two - or three -letter or a letter-number code . You can find these tire numbers and letters in the Tire Safety Group sorted list. This may be important for those who want to know whether the tire was made in the US.
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 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 does 55 mean on a tire?
For example, a tire size of P225/55 R15 tire, the 55 means that the height is equal to 55% of the tire’s width.
What does the letter P mean on a tire?
Letter P: The first letter at the beginning tells us which type of tire we have. In this case, we have a “P”, which means that it is a Passenger car tire. This means that it is made to a certain standard in the USA. You can also find the letters “LT” which means that they are designed for light trucks. If you find no number at all here, it means that the tires are made in Europe. Euro-Metric tires do also have different load capacities.
What is a radial tire?
A radial tire means that the layers run radially across the tire. Numbers 15: This number is the inner diameter in inch, or other words, what size of rims this tire fits on. In our example, this tire says it is a 15-inch tire, which means that we need 15″ rims.
What is load index?
The Load Index describes the total max weight that the tire can handle when it is fully inflated. The higher the load index rating, the more weight it can handle. You need a tire load index chart to see the exact numbers.
Is Tire Size Important?
The tires must fit your vehicle perfectly for proper operation. The first issue with improperly sized tires is the appearance. When you put on tires that are too small or too large for your vehicle, it isn’t going to look right.
How to tell when a tire was manufactured?
The date the tire was manufactured is listed after the DOT ID number . However, it is not presented in the usual fashion. Rather, the first two digits specify which week of the year the tire was made, and the last two digits specify the year.
How much weight can a tire hold?
Tires with a load index of 95 can hold up to 1,521 pounds. Those with an index of 126 can carry 3,748 pounds.
What is radial construction on tires?
The next item in the code specifies how the tire is constructed. Almost all tires available today are built with radial construction. This means cords of rubber were laid out radially, 90 degrees from the direction of travel. Bias-ply tires (where the cords are crisscrossed over one another) are sometimes used on trailers.
What is the sidewall of a tire?
The sidewall of a tire explains everything from its size to its mileage rating to the type of weather it can handle.
What does M+S mean on tires?
Some, but not all, tires will show an eighth and final item in the code. This is a severe weather rating. It may read M+S, meaning mud and snow. Some tires also have a snowflake symbol in this location. If your tires do not have the eighth item in the code, they are three-season tires not intended for use in heavy winters.
How many miles does a car drive a year?
The average American drives about 13,500 miles a year, and most new tires are good for between 40,000 and 70,000 miles.
Where is the maximum inflation pressure on a tire?
Usually located on the inner rim of the tire, in fairly small font, is the maximum inflation pressure. It is unsafe to inflate the tire beyond this point. However, it’s best not to use this as a guide when inflating your tires. Tires perform differently when carrying different weights, so your car’s weight affects the proper inflation level.
What do tyre sizes mean?
The code that is found on the tyres gives more than just the basic size. The size elements are essentially the tyre’s height and width. Tyre sizes will also vary depending on the type of vehicle i.e. van and lorry tyres tend to be larger/chunkier than car tyres. Read What Size Tyre Fits My Car? for more information.
What do the first three digits on a tyre mean?
The first three digits belong together and indicate the width of the tyre ( in millimetres). In the example above, the tyre is 195mm wide.
What does a radial tyre mean?
It means that the steel belt inner construction is angled at 90 degrees to the direction of travel, resulting in extra strength. Almost all new car tyres are radials. The next two digit number after the slash indicates the diameter of the wheel (in inches) - essentially how wide the wheel is across the centre.
