|
Category: Features Explained
|
|
Cruise control was invented in 1945. The first car to have this device fitted was a Chrysler Imperial in 1958. Where it is fitted, this feature allows the driver to set a constant driving speed for the car.
There are two good reasons for using cruise control. The first is that it allows the driver to maintain a pre-determined speed without keeping any pressure on the accelerator pedal. This makes long journeys at constant speeds a more comfortable experience. The second reason is to avoid unintentional speeding. Cruise control helps reduce this risk, especially when driving a powerful, quiet car on the motorway, where the perception of speed can be different.
Using Cruise Control
To set this control, the driver needs to first accelerate the car up to the cruise speed manually. The speed is then set by the press of a button. The system takes over the car’s accelerator to maintain a steady speed. This may vary ever so slightly as the car goes up and down gradients or around corners. This is because the system reacts to changes in speed as they happen rather than anticipating them, as a skilled driver would do. Cruise control does not apply the brakes in the event of over-speeding downhill.
Modern control takes its speed signal through the vehicle's Engine Control Unit (ECU). Most systems do not allow the use of the cruise control below a certain speed, usually 35 mph/55 km/h to discourage use in town driving.
When the driver pushes the brake or clutch, this has the same effect as switching the device off. Cruise control often includes a memory feature to resume the set speed as well as increase or decrease speed. Small adjustments, up and down, to the cruising speed can be made by tapping the appropriate button(s). Each tap adjusts usually adjusts the cruising speed by approximately one kilometre per hour (around two thirds of a mile per hour). When the cruise control is in use, the throttle can still be used to accelerate the car, but once the accelerator is released the car will then slow down until it reaches the previously set speed.
The use of cruise control is intended for long distance high speed driving. Used correctly, the feature does make such journeys smoother and less fuel will be used.
|
