TEMPORARY USE ONLY and the T in T125/80 R17
A temporary use spare tyre, built to get you to a repair: the T-type is designed for higher inflation pressures than standard and reinforced tyres, and its speed symbol may be low — M, for example, is 130 km/h.
What to do with it
Keep it at the pressure on its sidewall — 420 kPa (60 psi) for a T-type — and check it when you check the others. Drive within its speed symbol and the vehicle maker’s instructions, and replace it with a proper tyre as soon as you can.
Read the size on your tyre: the tyre size decoder →
- What it looks like
- A narrow spare whose size starts with T (T125/80 R17 99M) and whose sidewall says TEMPORARY USE ONLY in letters at least 12.7 mm high; the T-type also says INFLATE TO 420 kPa (60 psi).
- Set by
- UN Regulation No. 30, paragraphs 2.3.5 and 2.3.6 (definitions), 2.17.1.4, 3.1.11 and 3.1.11.1; 49 CFR 571.139, S5.5.5
In detail
- UN R30 2.17.1.4: “the letter ‘T’ in front of the nominal section width in case of T-type temporary use spare tyres”.
- UN R30 3.1.11 and 3.1.11.1: TEMPORARY USE ONLY in capitals at least 12.7 mm high, and on the T-type “INFLATE TO 420 kPa (60 psi)”.
- US FMVSS 139 S5.5.5: a tyre with a 420 kPa (60 psi) maximum pressure says “Inflate to 60 psi” or “Inflate to 420 kPa (60 psi)” on both sidewalls.
- Temporary spares are excluded from the US quality grades (UTQG).
What it does not mean
The T is not the T speed symbol (190 km/h): it stands in front of the width, not after the load index.
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 2.3.5 and 2.3.6 (definitions), 2.17.1.4, 3.1.11 and 3.1.11.1: “In the case of temporary use spare tyres, the words ‘TEMPORARY USE ONLY’ in upper case characters at least 12,7 mm high”; “in the case of ‘T’ type temporary use spare tyres, the legend ‘INFLATE TO 420 kPa (60 psi)’”. 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 — S5.5.5: “If the maximum inflation pressure of a tire is 420 kPa (60 psi), the tire must have permanently molded into or onto both sidewalls … the words ‘Inflate to 60 psi’ or ‘Inflate to 420 kPa (60 psi).’” Checked 2026-09-28.
- Michelin (UK): Tyre markings explained: How to read a tyre? — letters before the size: Michelin lists “T : Temporary (spare wheels)”. Checked 2026-09-28.