Auto start stop feature also known as a start stop system or idle stop feature is an engine technology that is used to achieve better fuel economy and reduce emissions in an internal combustion engine.
The auto start stop feature is common on hybrid vehicles but because of fuel economy concerns it is now becoming common for other vehicles with small and large engines to have the feature.
Some vehicles will allow you to manually disable the start stop feature by pressing a dedicated button or using a menu. Other vehicles
may automatically disable the feature if the battery charge level is low. Some vehicles may allow both methods of disabling the feature.
The start stop system functions by switching off the engine whenever the vehicle comes to an idle and automatically re-starts it when you're ready to drive off. The common applications of this will be at traffic jams, in traffic lights or at other intersections.|
For vehicles with an automatic transmission you just have to bring the vehicle to a stop
and keep your foot on the brake pedal. The system would detect that the vehicle is stationary and it will switch off the engine. Remove your foot from the brake with the transmission still in drive and the engine will restart.
For vehicles with a manual transmission you have to bring the vehicle to a stop, place the gear lever into neutral and release the clutch pedal for the engine to switch off. Pressing the clutch pedal would restart the vehicle.
Auto start stop systems uses the engine management system or another ECU to receive information from other systems in the vehicle to determine when the conditions are right for
the engine to be switched off and on.
Features such as air conditioning/climate control and other engine belt driven devices are often adjusted or re-designed to continue working properly when the engine switches off.
There may be several ways of restarting the engine but a common method is for an ECU to engage the starter or an electric motor automatically by sending an electrical signal to it in a similar manner to when the ignition is started manually.
The starter motor and other mechanical components used to start the engines are re-designed to handle the additional stress of constantly restarting the engine and the charge level.
The battery is the main component that must be monitored as a greater demand is placed on the battery to provide power to be constantly
re-starting the engine and to power belt driven devices while the engine is switched off.
More powerful batteries are usually required and the vehicle constantly monitors the charge level and other parameters of the batteries.
As with almost any feature, an auto start stop feature from one marque will be different from another in terms of smoothness of the
system, the time it takes to switch off and re-start and the method used to achieve the objective.