ATV, Car and SUV Tires

Two size formats, one rim diameter

Car and SUV tires use the metric code, for example 215/55R17 94W: width in millimeters, sidewall height as a share of width, R for radial, and the rim diameter in inches. The last part is the load index and speed symbol. ATV, trailer and garden tires use inch codes such as 27x8.50-15, giving overall height, width and rim diameter, with the dash marking a bias-ply build. Whatever the format, the rim diameter must match your wheel exactly.

Overall diameter matters when you change size. Keep the new tire close to the original height, because a taller tire throws off the speedometer and may rub in the wheel arch. On a quad the front and rear tires are often different sizes, so confirm the position before buying a pair. ATV tires are not meant for public roads unless the sidewall says so, and lawn and garden tires are built for light loads and low speeds.

Load range, ply rating and sidewall look

Load range letters show strength rather than a literal number of plies: D is 8-ply rated, E is 10, F is 12 and G is 14, with higher letters carrying more load at higher pressure. On passenger tires, SL means standard load and XL extra load; an XL tire needs higher pressure to reach its stated capacity. A stiffer tire rides harder, so choose the load your vehicle or trailer needs, not the highest available.

Sidewall codes are mostly cosmetic. BSW is a plain black sidewall, WSW a white sidewall, and RWL or ROBL mean raised white or outlined black letters. Tread pattern matters more: an all-terrain pattern grips on gravel and mud, while a highway pattern is quieter and wears longer on pavement. Replace tires in axle pairs, or all four, so the tread depth and diameter stay matched.

Questions about ATV, Car and SUV Tires

What do 94W or 116T at the end of a tire size mean?

The number is the load index, a code for the weight one tire can carry, and the letter is the speed symbol. W is rated for higher speeds than T. Choose a load index at or above the one your vehicle maker specifies, and keep the speed symbol equal or higher.

Can I put ATV tires on a car or the other way round?

No. ATV tires are built for low speeds, low pressures and a different construction, and car tires lack the cut resistance and tread of an off-road ATV tire. Fit only the tire type listed for your vehicle, in the size and load range your manufacturer gives.

Is a higher load range always better?

No. A higher load range has stiffer sidewalls and a higher maximum pressure, which gives a harder ride and less grip on a light vehicle. It helps when you tow or carry heavy loads. Match the range to the vehicle's or trailer's rated load rather than going as high as possible.