The sidewall inscription
What do the markings mean?

Nominal tyre width

The nominal tyre width is specified in millimetres.
Height/width ratio
The height of the sidewall as a percentage of the tyre width.

Design
Code for the tyre design: "R" stands for radial construction, "B" or "–" for diagonal construction.

Rim diameter
The rim diameter is specified in inches.

Load index
The load index shows the tyre's load-bearing capacity. Extract from the load index table:

Load index number	40	45	50	55	60	65	70	75	80	85	90	95	99	100
Permissible load in kg	140	165	190	218	250	290	335	387	450	515	600	680	775	800

Speed index

The speed index specifies the approved maximum speed. Extract from the speed index table:

Speed index	Q	T	H	V	W	Y
Permissible km/h	160	190	210	240	270	300

Other informationrf - reinforced

XL - extra load (used on specially reinforced tyres)

M+S - special identification for winter tyres (mud and snow)

DOT number
DOT stands for the American Department of Transportation. This provides a short manufacturer code, and the last four digits specify the date of manufacture (e.g. DOT xxxx1606 = week 16, 2006).

TWI information
TWI stands for "Tread wear indicator". When the tyre has become worn, the wear indicator will be at the same level as the surrounding tread surface. This means that the tyre has reached a tread depth of 1.6 mm, which is the legal minimum. Tyres must be replaced by this stage at the latest.

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