Wheel Alignment and Uneven Tyre Wear Explained

What Wheel Alignment Actually Means

Wheel alignment — often called tracking — is the adjustment of the angles at which your wheels sit relative to the road and to each other. Three settings do most of the work: toe, which is how much the front of each wheel points in or out; camber, the inward or outward lean viewed from the front; and caster, the tilt of the steering axis. Manufacturers publish a small tolerance range for each, and when your car sits inside that range, the tyres run flat and true, the steering self-centres neatly and fuel consumption stays where it should.

Knock a wheel out of that range and the tyre is no longer rolling — it's being dragged sideways along the tarmac, a fraction of a millimetre at a time, thousands of times a minute. That's the "scrub" you'll hear about.

Reading Uneven Wear Patterns

Your tyres tell you what's wrong before the steering wheel does. Run your palm across the tread and look closely at the shoulders.

• Worn inner or outer edge only — usually a camber or toe problem. If it's one edge of one tyre, suspect a bent component after a kerb strike.
• Feathered tread blocks — a saw-tooth pattern you can feel when running your hand one way but not the other. Classic toe misalignment.
• Cupping or scalloped patches — often worn suspension bushes or dampers, and sometimes alignment out of spec.
• Bald centre strip — usually over-inflation rather than alignment, but worth ruling out.
• Both edges scrubbed, centre fine — under-inflation, or a heavy right foot through roundabouts.

Uneven wear matters legally as well as financially. The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tread, around the whole circumference. A tyre can pass that test overall and still be illegal on one worn shoulder — and an MOT tester will fail it.

Why UK Roads Are Hard on Alignment

Our roads are a rough proving ground. Potholes, raised ironwork, speed cushions, high kerbs and the deep standing water of a British winter all put sudden loads through the steering and suspension. A single solid pothole strike at 30mph can bend a track rod end or shift a subframe enough to put your toe out by a visible margin. Add a decade of salt, grit and crumbling surfaces and it's no wonder alignment drifts.

Some cars are more sensitive than others. Vehicles with low-profile tyres, wide wheels or sporty suspension geometry show the effects quickly. So do cars with rear multi-link suspension, where a rear alignment fault can make the back end feel vague and wear a rear tyre on one edge.

Signs You Should Book a Check

You don't need to wait for a visible problem. These are the triggers I'd act on:

• The steering wheel sits off-centre when you're driving straight.
• The car pulls to one side on a level road, or wanders and needs constant correction.
• The steering feels vague or unusually heavy, or doesn't return to centre after a turn.
• You've hit a kerb, a deep pothole or a speed bump harder than you'd like.
• You've had steering or suspension work done — track rod ends, wishbones, dampers or a new steering rack.
• You've fitted new tyres, especially a full set.
• It's been more than 12 months or around 12,000 miles since the last check.

An alignment check is generally far cheaper than a pair of tyres, and many garages will inspect and report for a modest fee, then charge only for adjustment if it's needed. Ask for a before-and-after printout — those numbers are useful evidence if something feels wrong later.

What Happens During an Alignment Check

A modern check uses sensors or targets clamped to each wheel, with the car on a level ramp at normal ride height and with tyre pressures set correctly. The technician compares your readings with the manufacturer's specification and adjusts the relevant components — usually track rod ends for front toe, and eccentric bolts or shims for camber and rear toe.

Two things to insist on. First, pressures and tyre condition should be checked before measuring, because a soft tyre will skew the readings. Second, if a component is bent, worn or seized, an alignment is a waste of money until it's replaced — a good technician will tell you that rather than simply dialling in the numbers.

Looking After Alignment Between Checks

• Keep pressures at the manufacturer's figures — check them cold, monthly, and don't forget the spare.
• Rotate tyres front to rear if the manufacturer permits it, so wear evens out.
• Slow right down for potholes and speed cushions where you can, and take them square-on rather than at an angle.
• Avoid kerbing; even a gentle nudge at low speed can shift toe.
• Fix worn bushes, ball joints and dampers promptly — sloppy components let the geometry move about as you drive.

Spend twenty minutes a month checking pressures and tread, and half an hour once a year on an alignment check, and you'll usually get noticeably more life from a set of tyres. It's the least glamorous maintenance on the list, and often the best value.