Truck, bus & trailer tyres

The steer axle sets how the vehicle handles and how evenly the whole set wears. Steer patterns run four or five straight circumferential ribs for directional stability and even wear, with a reinforced shoulder to resist the irregular wear that kerbing and heavy front-axle loads cause.

Watch the load index. Front axle loads have climbed with heavier cabs and alternative drivelines, and a 315/80R22.5 156/150L gives 4,000 kg per tyre in single fitment — enough for a plated 8,000 kg front axle and no more. Where a heavier front axle or a crane-carrier chassis is involved the answer is usually a 385/65R22.5 or a 425/65R22.5 on a wide single. Our axle load calculator gives you the minimum index in a few seconds.

Drive patterns trade rolling resistance against traction. A closed, block-pattern drive tyre with a heavy tread depth gives grip and mileage but costs fuel; a shallower, more open regional pattern saves fuel but gives away wet traction in winter.

For mixed UK work we normally recommend a 3PMSF-marked drive tyre across the fleet rather than a seasonal changeover — the operational cost of swapping is almost always higher than the compound compromise. Drive tyres are also the position where casing quality pays back twice, because a drive casing that survives its first life is the one worth putting through the retread route.

Trailer tyres carry high loads and experience lateral scrub in yards and loading bays. Our dedicated trailer range covers these demanding applications, and we carry 5,000 or more trailer and towed-vehicle tyres alongside them for the light end of the market.

Work from the plated axle weight. A 9,000 kg trailer axle in single fitment needs 4,500 kg from each tyre, which is load index 160 — which explains why 385/65R22.5 160K is the standard tri-axle fitment. Load index 158 gives 4,250 kg and is not enough on that axle. Confirm the requirement against the vehicle plate.

Consider scrub resistance. For trailer applications exposed to sidewall damage, useful features include a reinforced sidewall, a kerbing rib and a bead area that will take repeated docking. Trailer patterns run free-rolling ribs at a shallower depth than a drive tyre; tread depth should suit the trailer application and its rolling resistance requirements.

Low-deck and 19.5 inch. Low-deck curtainsiders and step-frames use 385/55R22.5, 435/50R19.5 and 445/45R19.5, all of which are high-load, low-section sizes with very little sidewall to absorb impact. Kerb strikes on these go straight into the bead. They are also the sizes most often found flat-spotted after a trailer has stood loaded for weeks, so check pressures on anything coming out of long-term parking before it moves.

PSV work is its own discipline. City buses do enormous numbers of stops, kerb constantly and rarely get above 30 mph, so shoulder protection and scrub resistance matter more than rolling resistance. Coaches do the opposite — long motorway runs at speed, where heat build-up and speed rating become the governing factors.

Check the speed symbol against the vehicle’s maximum. J is 100 km/h, K 110 and L 120: a coach plated for 100 km/h needs at least a J, and several urban patterns are rated no higher than 80 or 90 km/h because they are built for kerbing rather than speed.

The 17.5 and 19.5 inch sizes are the fastest-growing part of the UK commercial market, driven by 7.5 to 18 tonne distribution and the rise of home delivery. These vehicles do high stop-start mileage on poor urban surfaces, with a duty cycle that punishes the shoulder and the bead far more than the crown.

Look for a reinforced bead and a kerbing rib. Most premature removals in this class are sidewall damage from kerbs, not worn tread, so repeated sidewall damage is a reason to review the pattern and casing specification.

On/off road work needs a cut-and-chip resistant compound and a self-cleaning tread, and it needs a casing that will survive site abuse well enough to be worth retreading.

Mixed-service patterns carry an M+S marking, often a 3PMSF as well, and usually a heavier casing specification than the highway equivalent. Expect shorter tread life on road than a pure highway pattern — the trade-off is that the tyre survives the site. If the vehicle spends most of its week on the motorway between two sites, a highway drive tyre with a mixed-service steer is often the cheaper answer than a full on/off road set.

The M+S marking is a manufacturer’s declaration about tread pattern. The three-peak mountain snowflake, 3PMSF, is awarded only after a measured snow grip test, and it is the marking European enforcement is moving towards. Several countries now require 3PMSF rather than M+S on steered and driven axles in wintry conditions, so any fleet running into Europe should be specified against the rules of the countries it actually visits, not against the UK.

For domestic work the practical choice is an all-season drive tyre carrying 3PMSF, fitted year round. A dedicated winter set is rarely justified on a UK fleet once the cost of storage, fitting and the two changeovers is counted.