4 WHEEL ALIGNMENT
If your tyres are not properly aligned, you will end up wearing the tyres out more quickly and potentially creating some driving hazards.
When tyres are misaligned, they wear out unevenly relative to each other and within each tyres own tread. The tyres will also likely show a rough and slightly torn appearance. When tyres wear unevenly, their life span is shortened. Since the tyres won't wear as long, you'll have to replace them more often, which can get expensive. More importantly, bad tread on your tyres means poor traction when you drive. Having bad tyre traction affects your car's ability to stop under all circumstances and it can increase the danger of bad driving conditions if there's mud or snow on the ground.
Image of uneven tyre wear due to misaligned wheel alignment