XL, Extra Load or Reinforced
A reinforced (extra load) tyre: its carcass is built to carry more than the standard tyre of the same size, at a higher inflation pressure. Michelin notes that the load index of an XL tyre is higher than that of the standard (SL) tyre of the same size.
What to do with it
If the vehicle maker specifies XL, keep XL. Inflate to the pressure on the vehicle placard or handbook for the load you carry, not to the maximum on the sidewall; an XL tyre reaches its higher load only at the higher pressure.
Read the size on your tyre: the tyre size decoder →
- What it looks like
- XL after the size (225/45 R17 94Y XL), or the words EXTRA LOAD or REINFORCED on the sidewall; older tyres may say REINF.
- Set by
- UN Regulation No. 30, paragraphs 2.3.4 (definition of ‘Reinforced’ or ‘Extra Load’) and 3.1.8; 49 CFR 571.139, S3 Definitions
In detail
- UN R30 defines it as a tyre in which “the carcass is more resistant than that of the corresponding standard tyre”, and 3.1.8 has it marked with the word REINFORCED or EXTRA LOAD. XL is the short form tyre makers use for it.
- The US definition is about pressure and load: “designed to operate at higher loads and higher inflation pressure than the corresponding standard tire”.
- Michelin writes that the marking REINF became XL, as opposed to SL (Standard Load), and describes a newer HL (High Load) class, introduced in 2021 for heavier cars such as electric SUVs.
- Vans use C tyres, not XL: that is a different regulation and a different page.
What it does not mean
XL does not mean extra large: the size is the same as the standard tyre. It is not a run-flat or a puncture-resistant tyre either.
Markings that go with it
Sources
Each document was fetched and read on the date shown; the clause is the one that sets this marking.
- UNECE, as published in the Official Journal of the EU: UN Regulation No. 30 — Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers, Revision 3 (OJ L 201, 30.7.2008) — paragraphs 2.3.4 (definition of ‘Reinforced’ or ‘Extra Load’) and 3.1.8: “‘Reinforced’ or ‘Extra Load’ describes a pneumatic-tyre structure in which the carcass is more resistant than that of the corresponding standard tyre”; tyres carry “The word ‘REINFORCED’ or the words ‘EXTRA LOAD’ if the tyre is a reinforced tyre”. Checked 2026-09-28.
- US National Highway Traffic Safety Administration, on eCFR: 49 CFR 571.139 — Standard No. 139, New pneumatic radial tires for light vehicles — S3 Definitions: “Extra load tire means a tire designed to operate at higher loads and higher inflation pressure than the corresponding standard tire.” Checked 2026-09-28.
- Michelin (UK): When to use reinforced tyres? — summary: “Reinforced tyres, formerly marked REINF on the sidewall (for ‘reinforced’), are now called XL (Extra Load), as opposed to SL (Standard Load).” Checked 2026-09-28.