We're going to break down what exactly camber is, why it's useful, and how much you really need?
When it comes to wheel alignment, the most important aspect to control is naturally going to be whether your wheels are tracking straight, or whether they run with toe-in or toe-out. This represents the brunt of the behaviour of your car, from the steering to the overall handling. But let's not forget that camber, the angle of the wheels from the vertical, is also pretty important.
We're not going to dive into the history of camber with incredibly old cars, which ran positive camber whether designed for racing or the road. In the modern history of camber, the purpose has been twofold for the most part. The first is to ensure that the tyre maintains a suitable contact patch with the road when you're cornering, and the second is to resist lateral loads and transmit them more effectively through the tyre.
If that sounds boring to you, just imagine it as letting you travel in corners more quickly with more grip. But simply increasing camber (negative camber, that is) doesn't quite work - regardless of what "stanced" out cars may have you believe. To understand why we don't go all the way, let's look at what problems may result out of too much negative camber.
Compromised Braking And Acceleration
As you can imagine, having the tyres angled to the road when you're travelling in a straight line (static camber, that is), also means that the contact patch of your tyres to the road is smaller than if you were running with the wheels completely flat to the road - or with zero camber. This means that it is harder for your tyres to slow down the car and to accelerate it, due to the smaller patch of contact.
Uneven Wear Over Time
Tyres wear out over time much like your eraser wears out when you rub out errant pencil marks. Naturally, if your tyres are angled to the road, the inside of the tyre (the part that's more in contact with the road) are more likely to wear out first if you're travelling in a straight line most of the time - which is going to be the case when you're on public roads.
Inconsistent Behaviour On The Limit
One of the nuances of having more extreme amounts of negative camber is that when you first start turning the steering wheel, your tyres actually have less grip than you would with zero static camber. This naturally is less and less as you increase the amount of negative camber, and depending on the type of tyre you have and the suspension setup of your car, it can make the car feel slightly vague and resistant to turning initially.
It is only when the car starts to roll and the tyres generate grip that the negative camber comes into effect and you start to feel higher levels of grip as the tyres adhere better to the road. In some cases, with tyres that simply don't generate enough initial grip, you can quite readily understeer off your intended line.
So How Do I Check If I Have Too Much Camber?
As is the case with many things, it's actually much easier to figure out the ideal camber setup if you're working with a race car. Yes, this sounds strange but many race car components and settings are actually easier to calculate and sort out as they deal with a narrower range of conditions - but we digress. How race teams would do it is to measure the temperature of the tyre at the inside, middle, and outside of the tyre.
Assuming the ideal pressures have been found, if you're running too much camber you will naturally see higher temperatures on the inside of the tyre than the outside. The idea for race teams is to adjust camber until there is a relatively small temperature gradient across the surface of the tyre. Since you're unlikely to drive as hard or as regularly as a race car driver would on a track, this isn't an option.
The second option requires a lot more time, and that's checking your tyre wear over the course of weeks, months, and potentially even years depending on your usage. Tyre wear, as we mentioned earlier, will indicate whether you are utilizing too much of the inside of your tyre rather than evenly wearing out the tyre across the entire surface.
And that's where we come down to chalking your tyres. Chalk rubs off relatively quickly, but not so quickly that you would lose the markings immediately. This method is adapted from what drivers in autocross sessions do as they don't have enough consistent competition runs to note what the tyres are doing and whether they are optimized for the course.
The idea is to drive your regular daily route to work and back, or what you would spend most of your time doing with your car. Do it a couple of times in a row and you'll eventually wear out the chalk marks on the parts of the tyre that you're using effectively. If you find yourself with chalk still on the outside edge of the tread and the shoulders, then you simply have too much negative camber because you're not fully utilizing the width of the tyre.
Obviously, not every car comes with adjustable camber - in fact, most won't unless you have aftermarket suspension and adjustable geometry. For the most part, the standard alignment settings a manufacturer provides you with will be the most broadly applicable setup for the road.
But for those who have gone aftermarket and aren't quite sure when they'll be going for competition next, it's probably best to wind back the camber settings to something more realistic.