The start-stop system does exactly what it promises in the car. It automatically switches off the engine if the vehicle comes to a standstill. And then automatically restarts when it’s time to move off. But is this really just to stop you wasting your fuel while stationary? Or is there something else behind it? Isn’t the aim of the system something else entirely than to save money?

What is a start-stop system?

It’s a system that is installed in the vast majority of modern cars. The purpose, which is often discussed, is to reduce fuel consumption. There are a really long list of different systems on the market, but at their core they all do the same thing. In hybrid cars, these systems allow the engine to be shut off when the throttle is low, when driving downhill or when accelerating from higher speeds. The start-stop system is especially useful for cars that spend a lot of time in heavy traffic.

Does start-stop reduce fuel consumption?

According to the Society of Automotive Engineers, depending on driving conditions, the start-stop function improved fuel economy by 7.27 to 26.4 percent during testing. Experts say the savings are much lower when people are constantly driving on the highway, where the engine virtually never shuts off. On the other hand, if drivers spend most of their time in the city with frequent idling, the technology can achieve legitimate reductions in consumption.

Does the system wear out the engine?

When it comes to longevity, all aspects related to the starter itself should be covered, but unfortunately, a higher number of start-stop cycles leads to increased engine wear if steps are not taken to prevent it. However, car and component manufacturers do everything possible to ensure that the engine does not wear out. For example, the technology activates only when the engine reaches operating temperature and deactivates and restarts the engine if the engine and oil temperature drops dramatically. Turbine wear is minimised by the comprehensive engine management features and the engine also prevents oil from returning to the oil pan.

━━ ( Source: Zé Maria /  Unsplash+ )

What else is the start-stop used for?

The start-stop system is not just designed to save people money. There is also talk that switching off the engine should reduce emissions in urban areas where drivers are more likely to be stuck in traffic for longer periods of time. Start-stop eliminates the time the car is idling. This is a good thing, since idling is what increases the amount of exhaust gases in the air.

Myths surrounding the technology

Research by the American Automobile Association found that start-stop technology led to a 5 to 7 percent improvement in fuel economy. These savings may seem small, but they add up over the life of the car. In any case, it is a myth that this system consumes even more fuel than a conventional car. There is also talk that the system wears out the battery. For the most part, modern start-stop systems are found in cars that have robust, high-capacity batteries. In some cars, a separate battery is used to restart the engine. In addition, a computer in the car monitors the charge level. If it decides that it is not sufficiently charged to start the car again, it will let the car idle and not shut off. The system is therefore very gentle on the battery.

Is start-stop better for the environment?

Clearly, this modern system reduces emissions. However, the real question is whether the pollution caused by the production of additional parts is offset by the reduction in emissions during the vehicle’s life cycle. Moreover, it is not clear how much waste is generated from this system at the end of the vehicle’s life. There are as yet no studies that address these issues. Thus, they cannot be answered.