295/80R22.5 vs 315/80R22.5: What's the Difference?

The two sizes at a glance

The figures below are typical. Exact dimensions vary slightly between brands and patterns, so check the maker's data sheet for the tyre you are buying.

Width: more rubber on the road

The extra 20 mm of width on a 315 spreads the load over a larger footprint. That helps on heavy steer axles, where a horse carries the engine, cab and part of the trailer's weight. A wider tyre also has more tread volume to wear through, which can mean more kilometres per tyre on heavy work.

The 295 is narrower and lighter. It rolls with slightly less resistance and suits trucks and buses that carry less weight per axle.

Height: what changes when you switch

A 315/80R22.5 is roughly 30 mm taller than a 295/80R22.5. That sounds small, but it affects:

• Speedometer and tachograph readings. A taller tyre covers more ground per revolution, so the truck travels a little faster than the dashboard shows.
• Gearing. The engine turns slightly slower for the same road speed, which changes pulling power on hills.
• Clearance. Check the wheel arch, mudguards and, on duals, the gap between the two tyres.
• Fifth-wheel and coupling height on horses, which rises slightly with taller tyres.

Load rating: the deciding factor

For most operators the load index decides the size. A 315/80R22.5 rated 156/150 can carry about 4,000 kg on a single steer tyre and 3,350 kg per tyre in dual. A 295/80R22.5 rated 152/148 carries about 3,550 kg single and 3,150 kg per tyre in dual.

Add up your heaviest axle loads and divide by the number of tyres on each axle. The tyre's rating must cover that figure with some margin. If a 295 is marginal for your loads, the 315 is usually the answer.

Can I swap 295/80R22.5 for 315/80R22.5?

Often the rims are the same, and many trucks are offered from the factory with either size. A swap can be safe when:

1. The vehicle maker lists the new size as approved for your model.
2. The rim width is approved for the new size.
3. There is enough clearance in the arches and between duals.
4. You change every tyre on the axle, and ideally all axles on the same drive line, so the diameters match.

Never mix a 295 and a 315 on the same axle or in the same pair of duals. The taller tyre carries more of the load and the shorter one scrubs, so both wear out early and the differential works harder.

Which one should you buy?

• Heavy horse on long-haul routes: 315/80R22.5 in most cases.
• Bus, coach or regional distribution truck: 295/80R22.5 is common and cost-effective. Many coaches also run 315/80R22.5. See our bus tyres page.
• Not sure: buy the size already on the truck, from the sidewall, unless you have a reason and approval to change.

Both sizes in stock in Harare and Mutare

Proclassic Tyres supplies 295/80R22.5 and 315/80R22.5 in steer, drive and trailer patterns. Tell us which size is on your truck now, what you carry and your routes, and we will recommend the right tyre and confirm today's stock and price on WhatsApp. Read our full 315/80R22.5 buying guide for more on patterns and load ratings.