There are a lot of things that determine how a car will drive. Whether it’s designed for a sporty, spirited ride with sharp steering response, or simply to navigate the road in a confident and comfortable manner, dampers and springs are only part of the equation.
The rest is related to the alignment of the car. Specifically, what are the camber, caster and toe settings of the vehicle. Together, these three determine how the car moves on the road. Depending on how they are set, the difference in handling and steering can be quite significant, and can even be used to maximize the purpose of the vehicle. The 2023 Lotus Emira will turn and operate very differently than the Rolls-Royce Spectre, and part of that is due to their respective alignment.
But how does camber, caster and toe adjustment actually affect handling? Let’s take a look at what each one does, and how adjusting them in one way or another changes the car’s behavior.
camel and toe
Camber and toe are the two most important alignment adjustments because they are based on the tire’s position and direction on the road. Let’s start with the first one.
Camber is basically the tilt of the wheel inwards or outwards from the center of the vehicle. Negative camber means the top of the tire is tilted more, while positive camber indicates it is pushed out. Generally, it is common to have a slight negative camber at factory alignment settings. This is because it helps to maximize the tire’s contact patch under cornering and load normally.
It is common for cars set up for track driving to have too much negative camber, usually through installing aftermarket components such as adjustable or longer lower control arms and damper top caps. The greater the negative camber, the larger footprint the tire will make on the road during cornering, thus, greater grip when cornering. The inside tire will also be flatter rather than bearing more pressure on the outside shoulder.
It’s easy to visualize toes: Look down at your feet and point them either out or in. Now, imagine looking down at a wheel and tire from above. If it is pointed outward: It has the toes pointing outward. Inside: Toe inward. The factory alignment usually has a small amount of toe-in as this aids acceleration and keeps the steering nice and straight. Like adding negative camber, adding more toe-out is consistent with performance driving because it aids turn-in and steering response.
There is also such a thing as a zero toe, which means they are not pointed to one side or the other.
Casters and how these settings affect handling (and tire life)
according to suspension mysteryCaster angle is “measured by drawing a line between the upper and lower pivot points of the front side. The angle between the drawn line and the vertical is the caster angle.” Front straight, mean, top and bottom pivot points. Meaning, what’s above and below the entire wheel, damper, tie rod, and control arm(s) assembly.
Positive caster is when the top point is further back than the bottom, neutral is when they are straight up and down, negative is when the bottom point is further back. Generally speaking, any degree of positive caster is ideal as it improves turn-in and feedback. This increases steering effort, but it’s not really a problem with power steering.
It’s important to point out that each alignment setting affects each other, and the ideal order of operations is to adjust camber, caster, then toe. They also help each other – more positive caster means the outside wheel will get more camber under cornering, improving grip.
We briefly discussed tire wear above – this is also a thing with increased negative height. This brings up an important point when determining the best alignment: understanding when changing it is considered, with tire wear pattern number one, followed by how the car rolls on the road. More negative camber and toe-out can lead to tramlining. Additionally, under braking, rear tires with more toe-in will increase rear-end stability, which can be a positive or negative depending on one’s needs.
When considering how adjusting camber, caster and toe to get the most out of a vehicle’s suspension and chassis is worth considering whether maximizing performance or tire life is one’s goal.
