Typically, car toe alignment is brought up only in the event of vehicular malfunctions. To this day, the most experienced drivers often fail to realise the substantial impact their vehicle’s toe alignment has on safety and performance. It is time to raise the bar and get the most out of your ride.
A misaligned toe could lead to potentially dangerous situations, particularly in cases where the vehicle starts to pull to one side due to a large pothole or curb. The steering shaft may bend as a result of such occurrences, consequently affecting car wheel alignment, and thereby restricting the driver’s control over the vehicle.
Furthermore, a damaged steering shaft may also trigger an unsolicited reaction from the Electronic Stability Program, or ESP for short, as the software could mistake driving in a straight line for a slide or skid.
How does toe alignment work?
In order to answer this question, we have to take a (tiny) step back. Let us begin with the shocking concept that car wheels are not perfectly parallel. In fact, they are actually slightly toed-in.
To understand why cars are designed this way, consider what happens to the front wheels of an FWD vehicle as it accelerates.
Each wheel generates a certain amount of force, which in turn tries to pull the car in its direction. This state often seems stable, as these forces are balanced on either side of the car. Yet, when the vehicle drives over a bump, one of the wheels suddenly gets more grip, causing instability. Consequently, it starts to swerve and requires corrections to stay on course.
To counter having to correct the direction all the time, both wheels are slightly turned inwards. The wheels generate opposing forces, making the whole process stable. Additionally, all the elements of the car suspension system and tyres are pre-loaded as a result, which positively impacts handling. It is not a flawless system, however, as slight understeer can be felt when tackling corners and curves.
What are the symptoms of misaligned wheels?
A vehicle with a front toe-in has a tendency to straighten the wheels when in motion. This is especially tangible when driving at higher speeds - the car will stay straight despite the driver letting go of the steering wheel. This is a desirable effect.
By the same token, letting go of the steering wheel is one of the simplest ways to diagnose any alignment issues. When your car pulls slightly to the left or right, this indicates it is time to adjust its toe alignment. In other words, the wheel toe is asymmetrical, and needs to be corrected to its intended symmetry.
Similarly, having to continuously move your steering wheel to keep your vehicle on-track calls for an appointment at the diagnostic station. This also holds true if you find your car turns to the right more easily than the left, and vice versa.
Driving with a suboptimal toe alignment will wear the edge of a tyre faster, leading to uneven tyre wear across all of your wheels, as well as diminishing the durability of the tyre itself.
How does toe adjustment improve car handling?
Interestingly, a vehicle with no history of accidents may still have a suboptimal toe alignment. This is because alignment can change over time due to replacements and wear of suspension system elements, be it ball bearings, steering shaft joints, or bushings. You should always check your wheel toe alignment is within the recommended range when getting any scheduled diagnostic work done.
Examples of front wheel suspension toe +0.5°It is also worth mentioning that the numerical toe value is not as significant as the symmetry between the wheels. Consider the following example:
- The first car has a right wheel toe of -0.1°, and a left wheel toe of +0.6°
- The second car has a toe of +0.25° on both wheels
While both cars have the same overall toe (+0.5°), the second car, which is symmetrical and balanced, will offer a much smoother experience.
The same principle applies to rear toe alignment. Symmetry is the key concept here, and it is with a multi-link suspension, such as in the Volkswagen Passat B6, where toe alignment can be freely adjusted, that it is even more crucial.
How is toe alignment calibrated for performance tuning?
For the average consumer, the default toe alignment is an all-purpose, factory-calibrated setting that emphasises safety on multiple road surfaces. This differs greatly from advanced motorsports, such as GT racing, where the prevalent use of RWD vehicles requires more specialised setups.
In rallying, toe adjustments are made according to the road surface - on smooth tarmac, with wider curves and higher average speeds, the front axle toe is positive, while the rear is zeroed, whereas on loose gravel roads, where the vehicle almost never moves in a straight line, both axles are set to negative.
While these settings are impractical and unsafe for regular road use, they are very effective in a competitive environment, providing professional drivers with more responsive steering.
Toe alignment is typically adjusted at pit stops before special rally sections. Suspension mechanics frequently dedicate several days of training to find the optimal wheel alignment for an event.
Why should I monitor the toe alignment of my car?
Incorrect toe alignment parameters often lead to increased rolling resistance, additional tread wear, and greater fuel consumption. Moreover, they may not always manifest themselves in the form of exacerbated handling.
Understanding the normal behaviour range of your vehicle is absolutely vital for its longevity and your safety. The hesitant response and jittery movement caused by wheel toe misalignment is something you could have got used to by now, but that does not make it acceptable.