Tyre safety checks: what you need to know

Basic tyre checks

Tyres must be properly inflated, in excellent condition, and not too old for your car to be safe. Quick, simple checks confirm whether everything is in order and are more important than many people recognise. Dangerous tyres have been the cause of countless of collisions.

Tyre pressure

Tyre pressure influences how your vehicle brakes, handles, and rides so check it frequently with a pressure gauge. An under or overinflated tyre can also wear out prematurely. To find the recommended pressure, check your owners manual, look inside your door frame or inside the fuel flap. If all of that fails, try Google. There may be varying recommendations depending if the tyre is at the front of your car, the back, if the car is heavily laden, or if it is light.

Tread depth

A tyre’s tread helps it clear rain, icy slush, and other such things from its path so it can stick to the road beneath. How effectively it works is greatly influenced by the depth of the tread. When the tyre is new, there is plenty of depth so it can clear a lot of debris. As the tyre’s tread wears it clears less debris, so there is less traction. On this basis, it is important to regularly check your tread depth with a digital or manual gauge.

In the UK, the legal minimum tread depth is 1.6mm across the central 75% of a tyre’s width and around its circumference. However, it is better to replace the tyre earlier if money permits.

Rather than a gauge, you can estimate the tread depth via the tyre’s wear markers which are small, black, rectangular bits of rubber. If the tyre is new, the markers sit deep in its tread at the bottom of the grooves. Once the tyre is at – or anything below – the legal limit the markers sit flush with the rest of the tread.

Tyre damage

A damaged tyre is far more likely to fail than a healthy counterpart. Failure could cause a serious collision. Check the tyre for bulges, punctures, and excessive cracking on its sidewall.

Tyre date code

A tyre’s performance can diminish with age even if it has only covered a few miles. Constant exposure to hot and cold weather takes a toll. On this basis, check the date code on the tyre’s sidewall to see when it was produced. Code 51 20, for example. The 51 reveals the week of the year. It is week 51 of 52. The 20 confirms the year. It is 2020. There is no definitive age that a tyre becomes unfit, but evaluate it more frequently as time passes.

Tyre size and specification

When you purchase a tyre, it has to be the right size and specification for your car to be safe. The owner’s manual reveals the correct specification via a code. Simply buy a tyre that has the same code on its sidewall. 215/50 R17 91 V is a common example.

The 215 reveals the tyre’s width in millimetres. The 50 is the height of the sidewall as a percentage of the width. The R proves the tyre has a radial construction and 17 reveals it fits a 17” wheel. 91 is a load rating which is how much weight the tyre can support. Finally, V is the speed rating. See tables below reveal more.

Tyre load ratings

Code	Load in kg	Code	Load in kg	Code	Load in kg
62	265	84	500	106	950
63	272	85	515	107	975
64	280	86	530	108	1000
65	290	87	545	109	1030
66	300	88	560	110	1060
67	307	89	580	111	1090
68	315	90	600	112	1120
69	325	91	615	113	1150
70	335	92	630	114	1180
71	345	93	650	115	1215
72	355	94	670	116	1250
73	365	95	690	117	1285
74	375	96	710	118	1320
75	387	97	730	119	1360
76	400	98	750	120	1400
77	412	99	775	121	1450
78	425	100	800	122	1500
79	437	101	825	123	1550
80	450	102	850	124	1600
81	462	103	875	125	1650
82	475	104	900	126	1700
83	487	105	925	127

Tyre speed ratings

Code	Speed in mph
N	87
P	93
Q	99
R	106
S	112
T	118
U	124
H	130
V	149
Z	150+
W	168
Y	186