Man driving a car with a United States flag hanging inside the vehicle.

Confirmed: The start-stop system can destroy your car and this is the real reason

Is the start-stop system really as good as they say? Here is the explanation for why it could be harmful to your car

The Start-Stop system has been promoted as an effective way to save fuel in cars. It turns off the engine when the car stops, which reduces emissions and fuel consumption. However, this seemingly harmless system can have negative effects if it's not used properly.

Many drivers are unaware that this system has limitations and can cause long-term damage. Although it offers savings at the gas station, constant use of Start-Stop in certain conditions, such as prolonged traffic jams, could create more problems than benefits.

Background image of a street with several parked cars and another image of a man with a gesture of doubt and an exclamation on his head
Traffic jams are one of the dangers for start-stop | Getty Images, Masson

How does the Start-Stop system really work?

The Start-Stop system is designed to turn off the car's engine when it stops for a short period, such as at a red light. This way, it achieves fuel savings and reduces emissions by not leaving the engine running unnecessarily. To achieve this, the vehicle uses a more robust battery than the standard one, usually AGM or EFB type, which can withstand a greater number of charge and discharge cycles.

Although this technology can be beneficial in certain contexts, such as urban routes with frequent stops, it's not always the most suitable option. According to some experts, in situations like traffic jams, the constant starting and stopping of the engine can result in premature wear of the battery and the starter motor.

The risks of using Start-Stop in prolonged traffic jams

In a traffic jam, the Start-Stop system is constantly activated, turning the engine off and on. This creates additional stress on the battery, which receives quick and shallow charge cycles. The starter motor is also forced to work more than necessary, which can lead to faster deterioration of these components.

Parking lot full of cars of different colors with a circle highlighting a waving United States flag
The engine can be affected over time | Fahroni, Alexander Grey

In addition, in many cars, the air conditioning depends on the continuous operation of the engine. When the engine turns off, the cooling system also stops, which can be uncomfortable, especially on hot days. This way, the fuel savings in traffic jams might not offset the additional wear being caused to the vehicle.

When is it better to deactivate the Start-Stop system?

If you find yourself in a long traffic jam, the most advisable thing is to deactivate the Start-Stop system. This will prevent unnecessary battery wear and allow the air conditioning to work continuously. In addition, if you have symptoms of a weak or aging battery, such as slow starts or the appearance of a "start-stop not available" message, it's crucial to turn off the system to avoid bigger problems.

Meanwhile, if you drive in the city with frequent stops at traffic lights, keeping the system active can be more beneficial. In those cases, the fuel savings can be significant and the impact on the battery won't be as relevant.

Is the fuel savings worth it?

The fuel savings offered by the Start-Stop system are real, but limited. In vehicles like an SUV that uses $2,000 worth of gasoline per year, the annual savings can range between $60 and $100, depending on driving conditions. Although these savings are valuable, they might not justify the cost of replacing an AGM or EFB battery, which can cost several hundred dollars.

In summary, the Start-Stop system has advantages, but also drawbacks. When used correctly, it can help reduce fuel consumption and emissions. However, in long traffic jams or when air conditioning is needed, it's best to deactivate it to avoid wear on key car components.