Finding out that your car does not have anti-lock brakes the hard way is not the sort of thing you want to do. Instead of waiting to discover that your vehicle lacks anti-lock brakes at a time when you desperately need them, I suggest asking someone knowledgeable about the vehicle in question (i.e. whoever you're borrowing it from, or whoever's selling it to you).
The main reasons for knowing this information before driving are:
- Assuming that your vehicle does have anti-lock brakes when it does not can lead to some rather nasty surprises — think "car wrapped around tree", "multi-car pile up", and "skidding into oncoming traffic".
- Assuming that your vehicle does not have anti-lock brakes when in fact it does makes for inefficient braking — the car is trying to lurch-stop itself while you're sitting there pumping the brake pedal. If the car has an ABS, just let the car do its thang.
Of course, it's better to assume that your car lacks an ABS than it is to assume it has one. Pump-braking when the car has anti-lock brakes only decreases your stopping time a little, whereas locking the wheels and skidding around on the road can lead to loss of property or life. Don't do that.
I do concede that you may find yourself in a situation that has not given you the opportunity to ask about the vehicle's brake status (i.e. driving your drunk-ass friend home, or carjacking). If you find yourself in such a situation, it is best to try to determine whether or not the car has an ABS before finding out The Hard Way.
A good way to do so is to brake suddenly and see whether the car's wheels lock up and you skid (no ABS), or whether it jerkily lurches to a stop (yes ABS). Before performing the sudden-stop test, make sure you're in a suitable location — you want a dry, even driving surface, free from pedestrians and other vehicles. It is not good to do this test on wet leaves, ice, or small children. Remember, the point is not to see how long it takes you to come to a stop, but rather to make the car use its ABS if it has one, and for as short a time as possible.
Finally, the age of the vehicle is not a good way to determine whether or not it has an ABS! Don't depend on how old you think the car is, nor how old your friend says it is. Do the test if you're unsure, or if your drunk-ass friend is a liar and a menace.
[ ] (r) 2004.1.18@10:31 sideways says as any professional driver will tell you, ABS simply is not as good as well controlled non-abs. But given that 99% of people aren't willing to spend the time and effort involved in learning to brake effectively in a nonABS car...