How much tyre life does under-inflation cost?

The Technology & Maintenance Council of the American Trucking Associations puts a constant 20% under-inflation at 25% faster tread wear and 30% less tyre life. Ten psi low also costs about 1% in fuel. Michelin treats a tyre 20% below its label pressure as a flat, because the casing has already been overheated.

How do I tell which wheel-end part is eating my tyres?

Read the wear pattern. Inner shoulder scrub with a hot hub points to a worn hub bearing. Slow, repeat pressure loss points to a bent rim flange or a rough bead seat. Oval stud holes mean stretched wheel bolts. Feathering across the steer ribs means toe error from the king pin or steering joints. A dual pair with different rolling radius drags and overheats both tyres.

Your Tyres Cost More. Something Is Eating Them.

Q: Why are truck tyres more expensive in 2026?

Raw material. Natural rubber on the Shanghai Futures Exchange closed at RMB 20,645 a tonne on 9 October 2026, a nine-year high and about 28% up on the year, and the raw-material cost index for all-steel truck tyres is around 25% higher than a year earlier. Since September more than 60 tyre makers have issued over 70 price letters, mostly 2-5% - the fourth round this year.

The short version: ① Natural rubber is at a nine-year high, and more than 60 tyre makers have issued over 70 price letters since September, mostly 2-5%. ② The Technology & Maintenance Council found that 20% under-inflation costs 30% of a tyre’s life, and about 90% of tyre failures start with inflation. ③ Much of that begins at the wheel end: hub bearing, rim, wheel bolts, king pin, dual match.

A tyre that should give 90,000 km often dies at 45,000. The tyre is rarely the reason – the parts holding it decide how it wears.

1. The price move you cannot argue with

Natural rubber on the Shanghai Futures Exchange closed at RMB 20,645 a tonne on 9 October – a nine-year high, up 28% this year. The raw-material cost index for all-steel truck tyres is about 25% higher than a year ago, and 60+ tyre makers have issued 70+ price letters at 2-5% since September – the fourth round this year.

Infographic: natural rubber closed at RMB 20,645 a tonne on 9 October 2026, a nine-year high; all-steel tyre raw-material cost index up 25% year on year; more than 70 price letters from 60+ tyre makers at 2-5%

On a ten-tyre set quoted at $250 each, a 3-5% letter adds $75-125. Paying that twice, because half the tread went to a bent rim, is the expensive part.

2. Thirty per cent goes before the tread does

The Technology & Maintenance Council of the American Trucking Associations measured it: a tyre run 20% below its label pressure wears 25% faster and loses 30% of its life. Ten psi low costs about 1% in fuel. Michelin’s rule is blunter – 20% below the label, treat it as a flat.

Chart: a tyre run 20% under-inflated keeps only 70% of its normal life and wears 25% faster; about 90% of tyre failures trace back to inflation (TMC)

One casing: 90,000 km at the right pressure becomes 63,000 at 20% low. A slow leak hides well – a bent rim flange, a tired valve, a rough bead seat.

3. Five wheel-end faults, and the mark each leaves

Read the tyre, then check the part that made the mark.

1. Hub bearing. Play lets the wheel tilt, the inner shoulder of the inner dual scrubs and the hub runs hot. Jack the axle, hold the tyre at 12 and 6 o’clock, push and pull. Any movement or growl, and the rear hub AZ9231340909 or front hub 99000410066 comes off.

2. Rim. A bent flange or rough bead seat leaks air slowly – the permanent under-inflation of section 2. The steel rim 22.5×9.00 DZ93259619014 costs a fraction of the tyre.

3. Wheel bolts and nuts. Stretched bolts lose clamp load: the wheel shifts, the holes go oval, then a stud shears at speed. Replace bolts with the hub – wheel bolt 81.45501.0083, 35CrMo, class 12.9.

4. King pin and steering joints. Wear becomes toe error, and steer tyres feather across the ribs. Same direction on both sides points to axle alignment; opposite ways points to toe. Check the king pin kit WG9719410031, drag link end and ball joint WG9925240024.

5. The dual pair. Two tyres of different rolling radius fight each other: the smaller drags, both overheat, both come off early. Match by measured circumference, not the sidewall number.

Infographic: five wheel-end faults and the tyre mark each leaves - hub bearing causes inner shoulder scrub, a bent rim causes a slow leak, stretched wheel bolts oval the holes, worn king pins cause feathering, mismatched duals drag and overheat

4. Twenty minutes, before you buy rubber

Jack one corner. Shake the wheel at 12-6 and 3-9, spin it, watch the rim edge for run-out. Torque every nut. String-line both steer sidewalls. Tape both tyres in each dual. Then set pressure cold, against the load table, and write the date on the hub.

Infographic: the 20-minute wheel-end check - shake the wheel, spin it and watch rim run-out, torque every nut, string-line the steer tyres, tape both tyres in each dual

A hub, a rim, six bolts and a king pin kit cost less than two drive tyres. Spend on steel, save rubber.

The bottom line

When rubber gets dearer, the cheapest saving is the wheel end. Fix the part that eats the tyre before you buy another one.

Running HOWO or SHACMAN trucks? Send the number cast on your hub, rim or king pin – or a photo of the worn part – and we quote within one working day. Related: knock from the rear, suspension and steering parts.

Cover photo: truck wheel hub and wheel nuts. Photohelp13, CC BY-SA 4.0, via Wikimedia Commons.