Can I safely add camber to my wheels?
It is increasingly common to see "tuned" cars (or, more rarely, pickup trucks) with extreme camber settings - in other words, with wheels and tires that are noticeably tilted relative to the vertical. Some owners may wonder if changing the camber this way is a good idea, or they may already know they would like to do it but want to make sure it's safe.
To decide if changing a car's camber is a good idea, it's important to first understand what camber is and what it does. Camber is the term used to describe the deviation of a car's tires from the vertical when viewed from the front or rear. When the tops of the tires are closer to the center of the car than the bottoms, this is called negative camber; the opposite, where the vertices are tilted outward, is called a positive kink. The camber angle is measured in degrees, positive or negative, from vertical. It is important to note that the camber is measured when the car is at rest, but the angle can change when cornering.
The first thing to understand about proper camber settings is that vertical camber - zero degrees - is almost always theoretically better if it can be achieved. When a tire is vertical, its tread rests directly on the road, which means that the frictional force required to accelerate, decelerate, and turn is maximized. In addition, a tire that is directly on the pavement will not wear as quickly as one that is tilted, so the load is only on the inside or outside edge.
But if vertical is better, why do we need camber adjustment at all and why would we even adjust to anything other than vertical? The answer is that when a car turns, the tires on the outside of the corner have a natural tendency to lean outward (positive camber), which can greatly reduce cornering ability by causing the tire to move on the outside edge; creating some inward lean (negative camber) of the suspension when the vehicle is at rest can compensate for the outward lean that occurs when cornering. (The inside tire leans the other way and theoretically positive camber would be good for it, but we can't adjust both and the outside tire is generally more important.) The manufacturer's camber settings are a compromise between zero camber (vertical), which is best for straight-line acceleration and braking, and negative camber, which improves cornering performance.
What happens when the camber changes beyond the manufacturer's recommended settings? Usually when people think of changing camber, they think of adding negative camber or inward tilt. To some extent, adding negative camber can increase cornering power at the expense of braking efficiency (and tire wear), and a very small change in this regard - a degree or less - may be OK. However, every aspect of performance suffers at large angles. Extremely negative camber (or positive, although this is less common) can help achieve a certain look or accommodate certain suspension modifications such as airbags, but vehicles with such modifications may not be safe to drive because they simply won't be able to move. brake well.
Racing car mechanics choose the right camber for racing their cars; often this will involve more negative camber than would be appropriate on a street vehicle, but other settings are possible. (For example, racing cars with oval tracks that only turn in one direction often have negative camber on one side and positive camber on the other.) Understand that tire wear will increase.
But on a street car, safety should be a top concern, and sacrificing a lot of stopping power for a marginal cornering advantage just isn't a good deal. Camber adjustment within or very close to the manufacturer's recommended tolerances should be considered safe, but far beyond this range (and here even a single degree is a big change) braking performance can drop so quickly it's a bad idea. Some like the look and others think the cornering advantage is worth it, but in any car that will be driven on the streets, extreme camber is just not safe.
Another note about cars that have been significantly lowered: sometimes these cars have extremely negative camber, not because the owner intended, but because the lowering process has changed the camber. It is important to remember that any suspension change can affect safety; in the case of a lowering resulting in excessive camber, the lowering itself may not be dangerous, but the resulting camber may be dangerous.
