What Is Wheel Alignment?

Have you been told your car needs a wheel alignment or are you thinking of getting it done for a performance benefit? Wheel alignment really is a crucial factor that has a significant impact on your car’s handling, performance, braking capability and tyre wear - not to mention fuel consumption!

Accurate alignment settings can make or break a car. They can drastically improve the feedback given to the driver through the steering wheel, making a vehicle safer and more enjoyable to drive… and wheel alignment doesn’t cost the Earth, either. In fact, we’d argue there are fewer more beneficial services to treat your car to - in terms of bang for your buck, wheel alignment is hard to beat.

But what exactly is wheel alignment? How is it adjusted, and what do technicians use to get the job done? As one of Britain’s premier suppliers of wheel alignment machines, we know these are questions our customers often get asked. So, without further ado, let’s answer them!

How is alignment adjusted?

To perform an alignment on a vehicle, you first need the correct tools and equipment; most alignment specialists use tailor-made alignment machines. In a nutshell, a receiver unit is placed on each wheel and linked up to the main alignment system, which sits in front of the car. That system communicates with each receiver unit, precisely measuring the angle each wheel is at and determining the relationship between each wheel.

The car is typically placed on a four-post lift and raised up into the air, allowing adjustments to be made from underneath. Different vehicles have different adjustment methods, but the tool used generally remains the same: a trusty spanner!

The technician will input your registration number into the machine and make adjustments to match your car’s alignment specifications to the manufacturer recommendations. A computer screen shows them how far out each parameter is - each one will turn green when it’s adjusted correctly.

Toe

The most commonly-adjusted wheel alignment parameter is toe. If you just opt to have your car’s ‘tracking’ checked, you can expect a straightforward toe adjustment - although toe is perhaps the most crucial parameter to get right.

Looking down on the top of the wheel as you stand by the car, toe is the amount the wheels are ‘turned’ when the steering wheel is straight. If the front or rear wheels point outwards when the car is driving straight ahead, the car has ‘toe out’. If they point inwards, it has ‘toe in’. Both have their place, but excessive toe is never a good thing; not only can it impair handling and braking, it will result in dreadful tyre wear.

Camber

Looking at your car from the front or back, camber is the angle your wheels sit at relative to being vertical. Negative camber means the top of your wheel is angled inwards, towards the body of the car, while positive camber means the top of your wheel is poking outwards. If your wheels are standing straight up, they have zero camber.

Positive camber is pretty much never beneficial for handling or performance - most manufacturers recommend a little negative camber for optimal handling, although too much can again result in excessive tyre wear and a lack of grip.

Caster

Looking at your vehicle from the side, caster is visualised by how far forward or backwards your wheels are in the arches. Most standard vehicles have very little wiggle room for caster adjustments, so this parameter often won’t need to be adjusted much. It’s still important to make sure it’s correctly set, however, as caster affects steering feedback and tyre wear.

Thrust angle

Thrust angle is a measurement involving the front and rear axles, and the four wheels and tyres of the vehicle.

On a standard road car, the front and rear axles of the vehicle should be parallel, and a line drawn straight forward from the centre of the rear axle should intersect the front axle exactly in the centre too. So, when you accelerate (apply thrust), the vehicle will accelerate in a straight line. But if the rear axle isn’t parallel with the front axle, or if the rear toe is incorrectly set, the rear of the car will try to push the car to the left or right, which will have to be corrected by steering one way or the other.

Aside from all the other issues associated with wheel alignment, thrust is particularly critical on modern cars with advanced driver assistance systems (ADAS), which rely on cameras and radar to see the road straight ahead.

Premium wheel alignment machines

Want to learn more about the machines used to check and adjust wheel alignment settings? Explore our range of premium wheel alignment machines today and discover how they work!