TL;DR: Road noise that gradually gets worse is almost never “just the tyres getting old.” The usual culprits are uneven or cupped tread wear, a worn wheel bearing, an alignment fault chewing the tread, or a switch to a chunkier tread pattern. The quickest test: a bearing hum changes as you turn; tyre noise changes with the road surface.

Why does my car’s road noise keep getting louder?

A slow, steady rise in cabin noise over weeks or months is a symptom, not a fact of life. Something mechanical is changing shape or clearance, and the sound is the clue. In order of how often they turn up, the causes are uneven tyre wear (especially cupping and scalloping), a failing wheel bearing, an alignment problem that is scrubbing the tread, low or uneven tread depth, and a recent move to an aggressive all-terrain pattern. Each has a different sound signature, and you can narrow it down before you spend a cent.

How do I tell tyre noise from a wheel bearing?

This is the single most useful test, because the two feel similar from the driver’s seat. A tyre-related hum rises smoothly with road speed and gets noticeably louder on coarse chip seal or concrete than on smooth new asphalt. A wheel bearing produces a grinding or growling hum that changes when you change direction: gently weave across an empty lane, and if the noise grows as you steer one way and fades the other, a bearing is the likely offender. As a rule of thumb, noise that worsens when you steer left points to the right-hand bearing (more weight is thrown onto it), and vice versa. Bearing noise also tends to stay fairly constant regardless of road surface, and often peaks in a 60–90 km/h band.

Quick noise-source comparison

Clue	Tyre / tread	Wheel bearing
Changes when cornering?	No	Yes — the key tell
Changes with road surface?	Yes (louder on coarse seal)	Little change
Sound	Hum, drone or rhythmic thrum	Growl or grind
Vibration with it?	Sometimes (cupping)	Sometimes through the floor

Can uneven tyre wear cause a growing drone?

Yes — and it is the most common cause of a hum on otherwise smooth roads. Cupping (scalloped dips around the tread) and feathered or saw-toothed edges create a rhythmic slapping sound that grows as the pattern deepens. Because the wear is progressive, so is the noise. Run your palm across the tread: if it feels smooth in one direction and sharp in the other, that is feathering; if you can feel high-and-low patches, that is cupping. Both usually trace back to worn suspension, out-of-spec alignment, or skipped rotations. Learning to read the tread the way a fitter does — see our guide on reading tyre wear patterns like a mechanic — turns a mystery noise into a clear diagnosis. Rotating on schedule (as a guide, every 5,000–10,000 km; confirm your maker’s interval) is the cheapest way to head cupping off, and our note on how often to rotate in Australia covers the detail.

Does alignment make road noise worse?

Indirectly, yes. Incorrect toe or camber makes a tyre scrub sideways as it rolls, wearing one edge into a sharp, feathered lip that hums and then drones. The noise is the symptom; the alignment is the cause. If only one or two tyres are worn unevenly, or the car pulls or the wheel sits off-centre, get the geometry checked — the tells are covered in signs your car needs a wheel alignment. Fixing alignment stops new wear, but tread already scalloped will stay noisy until it wears past that stage or is replaced.

What about new tyres — is that noise normal?

Some tread patterns are simply louder. If the noise started the day you fitted a new set, particularly all-terrain or chunky patterns, that is design, not a fault — our guide to tyre noise on all-terrains explains the trade-off. A steadily worsening noise on tyres that were quiet when new is the opposite: something has changed and should be investigated.

When should I stop driving and get it checked?

Treat a growing growl that changes with cornering as urgent — a collapsing wheel bearing can seize. Book it in promptly. A worsening tread hum is less immediately dangerous but signals wear you will pay for either way; combine the check with a rotation and an alignment. If the noise arrives with a shudder, cross-check our pieces on vibration at 100 km/h and steering-wheel shake vs seat shake, and if tread is getting low, see when to replace tyres. A bearing hum on bigger-than-standard wheels is worth reading up on too — see wheel bearing wear caused by bigger wheels.

Common causes at a glance

Symptom	Likely cause	Next step
Hum louder on coarse roads, steady with speed	Cupped/feathered tread	Inspect tread, rotate, check alignment
Growl that changes when cornering	Wheel bearing	Inspect promptly — safety item
One tyre worn on an edge + noise	Alignment out of spec	Wheel alignment
Loud from day one on new AT tyres	Tread design	Normal — no fault

Bottom line: road noise that gets worse over time is a diagnosis waiting to happen. Corner-test for a bearing, feel the tread for cupping and feathering, and check alignment if one tyre is wearing oddly. A ten-minute inspection at a tyre shop usually names the cause — don’t write it off as age.

FAQ

Can a tyre get louder as it wears down?

Yes. As tread blocks shorten and wear unevenly, the tyre can hum or drone more, especially if it has cupped or feathered. Very low tread also changes the sound.

Is a humming noise always the wheel bearing?

No. Cupped tyres are the most common cause of a hum on smooth roads. Use the cornering test — bearing noise changes as you steer; tyre noise does not.

Will a wheel alignment fix road noise?

It stops the uneven wear that causes the noise, but tread already scalloped stays noisy until it wears out or is replaced. Align early to avoid the problem.

Should I worry about a growing growl before a long trip?

Yes. Have it checked before you travel, as a failing wheel bearing can seize. Confirm any repair need with a qualified mechanic.

Figures such as rotation intervals are a 2026 guide only — always follow your vehicle handbook and confirm any diagnosis with a licensed tyre fitter or mechanic. Suggested schema: Article + FAQPage.