25 Years ago, in Britain and Europe, the driving of automatic cars was quite rare.
Even rarer, were people choosing to learn to drive in an Automatic Car and take an automatic Driving Test. Well times are changing with many learner drivers, are simply opting to take an Automatic Driving Test.
Most people within 7 years of passing a manual Driving Test, opt to drive an automatic car anyway, as they are so much more relaxing to drive. Less foot stress and less mental stress in traffic; what could be wrong with that? Automatic Cars are safer, easier to drive and in many cases cheaper to maintain and run.
The Automatic Gearbox
Lets take a look at how automatic gearbox vehicles work, in a little more detail.
Firstly though, there are many different types of automatic gearboxes out there, some allowing manual selection of gears etc. So, firstly lets define what makes a car an “automatic”?
Well the answer is where the driver does not physically operate a clutch.
How does the Automatic Gearbox Work?
Most automatic gearboxes have a selector lever, that will let the driver select between ‘D’ (drive) ‘P’ (for park), ‘R’ (reverse), ‘N’ (neutral)
Select Park( P) only when the car is fully stopped and…….well when you are parked!
Simple. This position ‘locks’ the gearbox, so the car can go nowhere. The driver will still be able to operate a handbrake in some way, so double safety. How many drivers park a manual car on a hill and don’t leave it in gear, relying on a handbrake, so to find their pride and job is not where they left it on returning to the car?
Select ( R) reverse, the clue is in the name. This does the same as a manual car and the reversing light is automatically illuminated.
Selecting (N) Neutral does the same job as a manual car, breaking the link between the engine and road wheels. It is used for the same purpose as neutral in the manual.
So, imagine that you are driving an automatic car, waiting at a set of traffic lights and are the lead car.
You could simply leave the car in drive, with your foot on the footbrake, unless there were pedestrians close to the front of the vehicle.
If you are 4 cars back, you could put the automatic gearbox in neutral.
Rule 114 of the Highway Code States, You MUST NOT
- use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders.
At night, rather than blinding the driver of the vehicle behind when sitting at traffic lights, using Neutral and putting the handbrake on, can avoid the problem.
Selecting (D)” or Drive will allow the car to move forwards and select its own gear according to the speed and load requirements. So as the car goes faster, the mass of the vehicle becomes less, the gearbox senses that less power is required and the auto gearbox changes up.
Some older automatic cars have gearboxes which can get confused as a car goes down hill, changing up because the gearbox senses that the mass of the vehicle had decreased as the load is lifted.
This can sometimes cause the vehicle to increase speed at an undesirable time.
However, most of these automatics allow the driver to manually select a lower gear, to hold the speed of the car back with engine compression, rather than overheating the brakes, potentially causing loss of braking ( brake fade).
In snow or icy conditions, many auto gearboxes have a button that can be pressed for “ winter mode”.
This mode can work in various ways, but in effect applies less torque to the road wheels, avoiding wheel spin.
Automatic car drivers can usually manually select second gear, which would do the same job on snow and ice.
In Summary
A car is defined as ” automatic”, if the driver does not physically operate a clutch, however the auto gearboxes themselves are infinite in the way that they deliver the engines power to the road.