LT175/65R14 tire size

LT175/65R14 in numbers

LT175/65R14 works out at 22.96 inches (583 mm) tall and 175 mm (6.89 in) wide, with 113.7 mm of sidewall on each side of a 14 inch rim. One turn covers 1832 mm (72.1 in), so it turns about 546 times per kilometre and 879 times per mile, or 910 times a minute at 100 km/h. It is the shortest of the 170 light truck sizes listed here. The LT prefix puts it on the light truck load table. 175/65R14 has the same nominal dimensions but is rated on the passenger table, so the two are not interchangeable at rated load. No other light truck size in this catalog comes within 3 percent of its diameter; the nearest are LT215/45R17 (+7.24 percent) and LT215/40R18 (+7.91 percent).

What each part of LT175/65R14 means

175

Section width in millimetres, sidewall to sidewall at the widest point. Not the tread width, which is narrower.

65

Aspect ratio. The sidewall is 65 percent of the section width: 175 x 65 / 100 = 113.75 mm. A lower number is a shorter sidewall on the same width.

R

Radial construction. The R here is construction, not the speed symbol R. The speed symbol sits after the size, in the service description.

14

Rim diameter in inches. The bead seat diameter of the wheel this tire mounts on.

LT

LT-metric (light truck). What the prefixes mean

Dimensions LT175/65R14 implies

These are the nominal dimensions the size code implies. A real tire's measured dimensions depend on its mould, its construction and the rim width it is mounted on, so a manufacturer's specification sheet for a specific tire is the authority for that tire.

The overall diameter formula used here reproduces all 52 radial passenger design diameters published in an Indian vehicle standard to within 1.4 mm, 0.5 mm on average: AIS-044 (Part 2) Amendment 2, Annexure A.

Questions this size raises

What does LT175/65R14 mean?

175 is the section width in millimetres. 65 is the aspect ratio: the sidewall is 65 percent of the section width, which works out at 113.7 mm. Radial construction. 14 is the rim diameter in inches. The service type is LT-metric (light truck).

How tall is a LT175/65R14 tire?

22.96 inches (583.1 mm) in nominal overall diameter. That is the diameter the size code implies; a specific tire's measured diameter depends on its mould and the rim width it is mounted on, and the manufacturer's specification sheet is the authority for that tire.

What is the sidewall height of a LT175/65R14?

4.48 inches (113.7 mm) per side.

How many revolutions per mile does a LT175/65R14 turn?

879 revolutions per mile, from the nominal circumference of 72.1 inches. A loaded tire deflects and turns slightly more often than that, so a manufacturer's published revolutions figure usually runs a few percent higher.

The rest of the sidewall

The size is one line of a sidewall. What follows it decides whether the tire is legal on the vehicle at all.

• Load index table - the number after the size, and the mass it stands for. Must meet or exceed the vehicle placard.
• Speed symbol table - the letter after the load index, including the ZR, W, Y and (Y) cases.
• DOT date code - how old the tire is, and why a three digit code is not the same as a four digit one.
• Every other marking - UTQG grades, load range letters, M+S against the three peak mountain snowflake.
• Compare LT175/65R14 against another size - diameter, clearance and speedometer error side by side.