These values are always compared with the manufacturer’s guidelines, which can differ according to model, year of construction and even equipment level.
This is the angle at which the wheel is positioned compared to the vertical axis. Positive camber means that the top of the wheel tilts outward; negative camber when it’s tilting inward. Too much negative camber can generate wear at the inside of the tire, while too much positive camber generates wear at the outside. Zero camber means there’s optimal contact between tire and road when the car is driving straight ahead. Manufacturers often design a slightly negative camber to improve stability during cornering, but within strict tolerances. Positive camber, on the other hand, is rather used in (light) trucks, where the wheel positions tend to change towards zero camber due to the load.
This is the angle between the steering shaft and the vertical axis. A positive caster or steering shaft angle allows for stability when driving straight ahead and the automatic return of the steering wheel after cornering. We should note here, however, that steering gets heavier. These days, negative caster or forward tilt and neutral caster are avoided because of instable steering and driving behavior. The arrival of servo control has ensured that modern vehicles are nearly always equipped with a positive caster, ranging from 2° up to sometimes more than 6°, according to type and segment. Caster cannot always be adjusted, except in sports or premium cars with adjustable track control arms.
Toe refers to the direction in which the wheels are positioned seen from above. Toe-in means that the wheel fronts are pointing to each other; toe-out means that they are pointing outward. Depending on the type of vehicle and the drive, both toe-in and toe-out are applied in practice (FWD with toe-out; RWD with toe-in). Incorrect track adjustment causes increased tire wear. This value has the highest impact on the steering precision.
For each model, manufacturers provide specific guidelines with both chosen values and tolerances (mostly in degrees or millimeters, per axle). These are included in the alignment software or the technical documentation of the vehicle. These guidelines take into account the following:
Only measuring isn’t enough: an experienced technician must be able to also interpret deviations according to the context. For example:
Furthermore, it is crucial to understand that symmetry between left and right side is sometimes more important than absolute values.
Professional wheel alignment requires more than just modern equipment. It also requires insight into vehicle technology, interpretation of data as well as manufacturers knowhow. Anyone mastering this expertise will not only deliver a safe car that is driving perfectly, but will also stand out as a subject specialist in an increasingly technical work environment.
Wheel alignment for experts: how to do this, explained step-by-step in a checklist.
Each intervention at the suspension or steering parts directly affects the wheel positions. The smallest deviation in camber, caster or toe has an impact on tire wear, changed driving behavior and vehicle stability.
How to replace strut mounts in a few steps.
