Humming or roaring that rises with speed

A hum, drone or roar that gets steadily louder as the car goes faster is more often a worn wheel bearing than a tire problem. If it is a bearing, we cannot help you and you need a mechanic, so find out which it is first. There is a thirty-second test, and you can do it yourself on a quiet road.

The gentle swerve test

Find an empty stretch of straight road and hold a steady speed where the noise is clearly audible, usually between 40 and 55 mph. No radio, windows up.

Now weave gently. Ease the car a few feet left as if changing lanes slowly, hold it, then ease back right and hold it. Small, smooth inputs. You are not swerving, you are transferring weight from one side of the car to the other.

The noise changes noticeably as you weave, louder one way and quieter the other: that is a wheel bearing. Leaning the car loads that side more heavily, and a damaged bearing complains under load. As a rule of thumb the bearing is on the side that gets quieter when you unload it. Confirm with a mechanic rather than buying a part on the strength of it.

The noise stays the same through the weave: that points at the tires. Tire roar comes from tread hitting the road and does not care much about small weight transfers.

Bearing manufacturers describe humming, rumbling and growling that changes with a shift in load as characteristic of wheel hub bearing damage, and note that the same sounds can also come from tires or the drivetrain, which is why the test matters.

If it is a bearing: go to a mechanic

We supply and fit tires and we do mobile puncture repair. We do not do wheel bearings, hubs, brakes, alignment, rotation alone or balancing alone. If the swerve test points at a bearing, this page has done its job and the next call is to a repair shop.

A worn bearing usually gets louder over weeks or months rather than failing overnight, but it does not recover and a badly worn one can seize.

Other bearing signs: a growl that continues when you coast in neutral, because it depends on road speed and not engine speed; play if you rock the wheel at twelve and six o'clock with the car jacked up; and sometimes a warm hub. Tell the shop which direction made it louder.

If it is the tires: what kind of noise is normal

Not every tire hum is a fault.

Tread pattern noise. All-terrain and winter tread blocks are loud by design, and the noise rises with speed. If the car has sounded like this since the tires went on, that is what you bought.

Cupped or scalloped wear. The tire fault that most often sounds like a bearing. Worn dampers or a long spell without rotation let the tire bounce microscopically, wearing a repeating pattern of high and low patches around the tread. The result is a rhythmic roar that rises with speed. Run your palm around the tread: cupping feels like a washboard.

Feathered wear from toe misalignment. The tread ribs wear sharp on one edge and rounded on the other. Slide your palm across the tread inward and then outward: one direction feels smooth and the other catches.

Underinflation. A soft tire deforms more, transmits more noise and wears its shoulders away. Check all four against the placard in your door frame first.

Be honest about the last two. Cupping and feathering are caused by suspension and alignment, and new tires fitted to the same car will wear the same way again. We sell tires when the tread is genuinely finished, but the cause needs a shop that does alignment and suspension work, which is not us.

What is definitely not this

A whine that rises with engine revs rather than road speed is drivetrain. A grinding only when braking is brakes. A rhythmic thump rather than a hum is covered on thumping noise from a tire, and a click on clicking sound from a wheel.

Where we do come in

If the tread is worn out, cupped past use, or feathered badly enough to be loud, replacing the tires is a real fix. We come to your home or workplace, supply tires matched to the vehicle placard, fit them, balance them and torque the wheels. When to replace tires covers the thresholds, find your tire size gets us the right stock, and how many tires do I need covers replacing fewer than four.

Get the alignment or the dampers sorted too, otherwise the new set wears the same way.

Questions people ask

• Is a humming noise that gets louder with speed a tire or a wheel bearing? More often a bearing. Weave gently left and right at a steady speed: if the noise rises and falls as the car leans, it is a bearing. If it stays constant, it is more likely the tires.
• Do you replace wheel bearings? No. We supply and fit tires and do mobile puncture repair. Bearings, hubs, brakes, suspension and alignment all need a repair shop.
• Can worn tires sound like a bad wheel bearing? Yes. Cupped or scalloped tread produces a rhythmic roar that is easily mistaken for a bearing. The swerve test and a hand run round the tread separate them.
• Is it safe to drive with a noisy wheel bearing? It usually degrades over weeks rather than failing suddenly, but a badly worn bearing can seize, and that is serious. Get it looked at rather than waiting for it to get louder.
• Will new tires cure the noise? Only if the tires are the cause. If the tread is cupped or feathered, the suspension or alignment that caused it will do the same to a new set unless it is fixed too.
• My tires have been loud since the day they were fitted. Is that a fault? Probably not. Aggressive all-terrain and winter tread patterns are loud by design and get louder with speed. A noise that appeared later on tires that were quiet before is the one to investigate.