As governments introduce stringent emission targets for vehicles, manufacturers are looking for ways to reduce emissions and improve the engine’s efficiency. There are many paths this can take; from reducing engine volume, introducing turbo chargers and superchargers and increasingly sophisticated engine management and fuel injection systems. Why not just turn the engine off?
Many new cars have idle stop technology built into them. In traffic, if the car is stationary and a number of prescribed criteria are met, the engine is shut down and will restart typically once the brake pedal is released. Some of these criteria include;
- The engine at operating temperature
- The air con is not set to demist or max
- The steering wheel is close to the straight ahead position (or not being turned)
- The brakes are applied
There are a number of different systems that either use the battery and starter motor to restart the engine or those like the Mazda I Stop system that is smart enough to know the exact position of the engine and can inject some fuel, generate a spark and use the starter motor minimally. This happens within a third of a second. The included diagram depicting the I Stop operation is courtesy of VACC's Technical Department.
Bosch, and some European vehicle manufacturers, simply use a more powerful and durable starter motor to restart the engine.
Naturally there is a lot of technology to operate these systems and things can go wrong; battery, starter motor, alternator, sensors, wiring and switches. As you can imagine the battery is not your average one as it needs to be powerful enough to run the car’s electrics without the alternator charging it for extended periods. This drains the battery but it has to be strong enough to restart the engine time and time again. Typically a warning light/s will come on the dash board to indicate a problem and you will need to go to your A Grade Automotive Network professional for them to diagnose and fix the problem.
A more fuel efficient car means less time and money filling it up; good for you and the environment.