L4S Tread Code
L
Service category — which machineLoader and dozer
Wheel loaders and dozers working a face: short cycles, sharp material, and sidewalls up against a muck pile.
4
Tread type and depthSmooth Deep Tread
Smooth Deep Tread
ETRTO
The same code under the other standardSmooth Deep Tread
ETRTO Standards Manual 2026 lists L-4S as a smooth deep tread. Using these codes at all is left to the individual tyre maker, so a tyre may be marked to ETRTO, to TRA, or to neither.
S
SuffixSmooth
No tread pattern: the whole depth is solid rubber, so there is the most possible material against cutting and the least possible grip. Chosen where the floor is sharp and traction is not the problem.
TKPH
What the code does not tell youNothing about load, or heat
A tread code says which machine and how much rubber. What the tyre can carry comes from its star rating, and whether it survives the haul comes from TKPH — the load and speed it can work at without overheating. A deep tread on a long, fast cycle is a tyre being cooked.
Standardised by ETRTO or TRA.