Tire Sidewall Symbols, Dates and Approval Markings Explained

The short answer

A tire sidewall carries four main groups of information. The size code tells you the tire type, width, sidewall proportion, construction, rim diameter, load capacity and speed capability. The DOT code is the US Tire Identification Number, and its last four digits give the week and year the tire was made. Approval and performance markings include the UTQG treadwear, traction and temperature grades for US passenger tires and the E-mark for tires approved under UN regulations. Usage markings include M+S, the three-peak mountain snowflake, maximum load and pressure, and rotation or mounting arrows.

Which markings appear depends on the tire type and the market it was approved for. A tire sold in the US must carry a DOT code. An E-mark appears only if the tire was approved under UN rules used in Europe and elsewhere, and many tires carry both. UTQG grades are required on most US passenger tires but not on winter-type snow tires, light truck tires or temporary spares. Light truck tires use their own size and load conventions.

Sidewall markings diagram

The layout below is an illustrative composite showing where common markings tend to appear. It is not copied from a real tire. Placeholders stand in for values that vary by tire.

  P215/65R15 95H                    <- size code, load index, speed rating
  M+S   [mountain/snowflake symbol]   <- winter and snow markings
  DOT XXX XX XXXX 2319                <- DOT TIN; 2319 = week 23 of 2019
  TREADWEAR ___  TRACTION _  TEMPERATURE _   <- UTQG (US passenger tires)
  MAX LOAD 690 kg (1521 lbs)          <- matches load index 95
  MAX PRESS ___ kPa (___ psi)         <- maximum, not recommended, pressure
  (E_) ______                         <- E-mark and approval number
  TUBELESS  RADIAL  -> ROTATION       <- construction and fitment notes

Reading the size code

Take P215/65R15 95H as an example. Each part has a fixed meaning:

Part | Meaning

P | Tire type: P-metric passenger tire. LT means light truck, T means temporary spare, and ST means special trailer. Metric sizes with no letter prefix (often called Euro-metric) are also passenger tires.

215 | Section width in millimeters, measured from sidewall to sidewall.

65 | Aspect ratio: sidewall height as a percentage of section width.

R | Construction: R is radial. D or B indicates bias or belted-bias construction.

15 | Rim diameter in inches.

95 | Load index: a code for the maximum load per tire. Index 95 equals 690 kg (1,521 lb).

H | Speed rating: the maximum sustained speed the tire is rated for under its rated load.

Common speed rating letters and their maximum speeds:

Letter | km/h | mph

Q | 160 | 99

R | 170 | 106

S | 180 | 112

T | 190 | 118

U | 200 | 124

H | 210 | 130

V | 240 | 149

W | 270 | 168

Y | 300 | 186

Some older or high-performance sizes include ZR in the size, as in 225/45ZR17. ZR marks a tire rated above 240 km/h (149 mph). The service description after the size gives the exact rating. XL, Extra Load or Reinforced means the tire carries more load than a standard-load (SL) tire of the same size, usually at a higher inflation pressure.

Light truck (LT) tire codes

Light truck tires are marked in one of two ways. A metric LT size such as LT245/75R16 reads like a passenger size, with an LT prefix. A flotation size such as 33x12.50R15LT gives the overall diameter (33 in), the section width (12.50 in), radial construction and the rim diameter (15 in), followed by LT.

LT tires often show two load indexes, as in 120/116Q. The first number is the load capacity when the tire is fitted singly. The second is the per-tire capacity when two tires are paired on each side of an axle (dual fitment, as on a dually pickup). LT tires also carry a load range letter. It replaces the older ply rating, which describes strength rather than the actual number of plies:

Load range B: 4-ply rating
Load range C: 6-ply rating
Load range D: 8-ply rating
Load range E: 10-ply rating
Load range F: 12-ply rating

European commercial van tires use a C suffix instead, as in 195/70R15C. Whether a passenger, LT or C tire suits a vehicle depends on the load and size the vehicle maker specifies for that model.

DOT code and date of manufacture

In the US, the DOT code is the Tire Identification Number (TIN) required by the National Highway Traffic Safety Administration (NHTSA). It begins with the letters DOT, followed by these parts:

Plant code: identifies the factory where the tire was made. New plant codes have three characters; older ones have two.
Size code: a short code for the tire size.
Optional manufacturer code: used by the maker for its own purposes, such as brand or tire line.
Date code: the final digits, giving the week and year of manufacture.

Tires made since 2000 use a four-digit date code: the first two digits are the week and the last two are the year. A code of 2319 means the 23rd week of 2019. Tires made before 2000 used three digits: the week, then the last digit of the year. Tires from the 1990s often added a small triangle after the code to tell that decade apart from the 1980s.

The full TIN, including the date, may appear on only one side of the tire. The other sidewall can show a partial code without the date. If you cannot find the date, check the other side, which may be facing inward on a mounted tire.

The date code shows when a tire was made, not whether it is still safe to use. Tire and vehicle makers publish their own guidance on tire age and inspection. The sources here do not establish a single replacement age, so check the guidance for your specific tire and vehicle.

Treadwear, traction and temperature grades (UTQG)

Uniform Tire Quality Grading (UTQG) is a US labeling system for passenger tires. It does not apply to winter-type snow tires, deep-tread tires, light truck tires, temporary spares, or tires on rims of 12 inches or smaller. The grades are assigned by the manufacturer based on government-specified tests. There are three:

Treadwear: a number relative to a reference tire graded 100. A tire graded 400 should wear about four times as long as the reference under the test conditions. Real-world wear depends on driving, roads, climate, inflation and maintenance, and grades are most meaningful when comparing tires from the same manufacturer.
Traction: AA, A, B or C, from highest to lowest. It measures straight-line braking on wet asphalt and concrete. It does not measure cornering, hydroplaning resistance or dry grip.
Temperature: A, B or C. It measures the tire's resistance to heat buildup at speed. C is the minimum level required by US federal standards. B corresponds to roughly 100 to 115 mph on the test wheel, and A to above 115 mph.

Winter, snow and ice markings

These three markings are easy to confuse because they mean different things:

M+S (also M/S or M&S): mud and snow. It is based on tread pattern geometry, such as the size of grooves and open spaces, not on a snow performance test. Many all-season tires carry it.
Three-peak mountain snowflake (3PMSF): a mountain outline with a snowflake inside. It means the tire passed a standardized traction test on medium-packed snow, performing better than a reference tire by a set margin. It is the marking that separates tested snow performance from tread design alone.
Ice grip symbol: a newer marking under UN regulations for tires that passed a specific ice-braking test. It is aimed at severe ice conditions, and a tire with this symbol is not automatically better on wet or dry roads.

Some regions and roads require winter-rated tires during certain seasons. Those rules vary by jurisdiction and are not covered by the sources used for this guide, so check the requirements where you drive.

The E-mark (UN/European type approval)

The E-mark is a capital E inside a circle, followed by a number, then an approval number nearby. It shows that the tire was type-approved under UN vehicle regulations, which are used across Europe and in many other countries. The number inside the circle identifies the country that granted the approval: for example, E1 is Germany, E2 France, E3 Italy and E4 the Netherlands. This is where the approval was issued, not necessarily where the tire was made.

A lowercase e inside a rectangle indicates approval under European Union directives rather than UN regulations. Additional suffixes near the approval number can show compliance with extra requirements, such as pass-by noise. The US does not use the E-mark. US tires are self-certified by the manufacturer to federal standards, which is shown by the DOT code. A tire with an E-mark but no DOT code is not marked for US sale.

Pressure and load markings

The sidewall lists a maximum load, in kilograms and pounds, and a maximum inflation pressure, in kPa and psi. The maximum pressure is the highest the tire is designed to hold. It is not the pressure to run on your vehicle. The recommended cold inflation pressure is set by the vehicle maker and is printed on the tire information placard, usually on the driver's door jamb, and in the owner's manual. XL and LT tires may need different pressures from standard-load tires to carry the same load, so follow the vehicle maker's or tire maker's load-inflation guidance when changing tire type.

Other common sidewall symbols

Tubeless or TL: designed to be used without an inner tube.
Rotation arrow: the tire must turn in the direction shown when the vehicle moves forward.
Outside or Inside: an asymmetric tire that must be mounted with the marked side facing that way.
TWI or a small triangle: marks where the tread wear indicator bars sit in the grooves.
Ply or construction notes: for example, the number and material of plies under the tread and in the sidewall.
Run-flat markings: makers use their own abbreviations, such as RFT, ROF or ZP. The sources used here do not provide a complete list, so check the specific maker's documentation.

What the sidewall does not tell you

Sidewall markings describe a tire's size, ratings, approvals and manufacture date. They do not tell you whether the tire suits a particular vehicle, what pressure to run, or whether its condition is safe. For fitment, use the size, load index and speed rating listed for your model and trim on the vehicle placard or in the owner's manual. For condition, combine the date code with tread depth and a check for damage, and consult a tire professional when in doubt.