What do the markings on a tractor tire sidewall mean?

Besides the size, a tractor tire sidewall carries several markings. They tell you how much load the tire carries, how fast it can go, whether it needs a tube and when it was made.

Load index and speed symbol: 141A8 / 138B

Radial tires usually show a code like 141A8. The number is the load index (each value maps to a load in kg, e.g. 141 ≈ 2,575 kg). The letter-digit is the speed symbol: A6 = 30 km/h, A8 = 40 km/h, B = 50 km/h, D = 65 km/h. Dual markings (e.g. 141A8 / 138B) mean the tire carries a little less load at the higher speed.

Ply rating: 8PR, 12PR

Bias tires usually express strength as PR (ply rating). It is a strength index, not a literal count of plies. In the same size, a higher PR carries more load and takes more pressure.

TL and TT

• TL (tubeless): holds air on a suitable rim without a tube.
• TT (tube type): must be fitted with an inner tube.

IF and VF

IF (Increased Flexion) and VF (Very High Flexion) radials carry the same load at lower pressure than a standard tire, reducing soil compaction.

Rotation arrow

Field tire treads are directional. The arrow shows which way the tire should turn when driving forward. Mounted backwards, the tire loses traction, does not clean itself and wears unevenly.

Date code

A four-digit code (e.g. 2324) gives the week and year of manufacture: week 23 of 2024. Tires that sat in storage for years can crack from rubber ageing even when unused.

Other markings

• R-1, R-1W, R-2: tread types for general field use, deeper tread, and rice/very wet fields.
• F-2, F-3: front steering tread types.
• I-1, I-3: implement and trailer tread types.

If unsure about a size, photograph the sidewall and send it to your tire shop. See also how to read a tractor tire size.