A small family car weighs around 1.5 tonnes. If its wheel alignments are slightly off centre, the tyres will wear unevenly. That means they won’t last as long as they should and you could get worse fuel economy too.
How to tell if your wheel alignments are out
Wheel alignments are quite simply how lined up the wheels are. If one or both front wheels are slightly out of line with dead straight, there will be at least one of two giveaways. The first is uneven tyre wear. You’ll notice this because one side of the tread will appear much more worn down all the way round the wheel than the other. The second is a vibration through the steering wheel. Your car constantly pulling to one side is another hint that your wheels aren’t quite dead straight.
Do your wheels need balancing?
You might also feel a vibration through the steering wheel if one of your road wheels needs rebalancing. Rebalancing is usually done when you get new tyres. The technician puts the wheel on a machine and it tells them where the wheel is out of balance. This is because although wheels are made to very fine tolerances, they must be absolutely perfect to rotate evenly. By adding tiny weights, the wheel can be made to rotate evenly.
A wheel that’s out of balance won’t wear consistently but that unevenness will be across the tread of the tyre rather than around it.
Why wheels need realigning?
A car’s suspension is tough but delicate all at once. It’s tough because it has to be to survive all the abuse it gets from our pockmarked roads. It’s delicate in that it only has to go out of true a tiny amount to have a profound effect on how tyres wear against the road.
What to do?
Although it’s not dangerous, having wheels that aren’t aligned can prove expensive so take the car to a garage. They will have either laser equipment or preferably, digital computerised kit. This will detect which direction the wheel isn’t properly aligned in and by how much. They can then adjust it accordingly.
What are the terms?
When a technician talks about toe in, they mean the leading edge of the wheel is pointing ever so slightly into the middle of the car. When they talk about toe out, the wheel’s leading edge is pointing away from the centre of the car.
Toe in will lead to a tyre wearing on its outer edge as this is effectively dragged along the road; toe out will see the inner edge wearing more.
Often it’s only the fronts
Front wheels are the most likely cause of a problem with wheel alignments because they have the weight of the engine over them as well as having to do the steering. And usually it’s only the ‘toe’ that needs adjusting. However, sometimes it can be a problem with the camber.
This is how vertical the wheel is. If its top is leaning into the vehicle, it’s called negative camber. If the top of the wheel is leaning away from the vehicle, it’s positive camber. Most vehicles have a tiny amount of positive camber to help with handling but it shouldn’t be sufficient to cause premature tyre wear.
When wheel alignment is checked, technicians should be able to tell if there are problems with the camber but it’s a more involved job that adjusting the toe.
I’ve been writing about cars and motoring for more than 25 years. My career started on a long-departed classic car weekly magazine called AutoClassic. I’ve since pitched up at Autosport, Auto Express, the News of the World, Sunday Times and most recently the Daily Telegraph. When I’m not writing about cars and motoring, I’m probably doing some kind of sport or working in my garden.