How Much Gain in Cars with Stop-Start Engines
Introduction
Stop-start engines are becoming increasingly common in new cars. They work by automatically turning off the engine when the car is stopped, and then restarting it when the driver presses the accelerator pedal. This can help to save fuel and reduce emissions, but how much gain can you really expect?
How Do Stop-Start Engines Work?
Stop-start engines use a variety of sensors to determine when the car is stopped and when it is safe to restart the engine. These sensors include:
* **Crankshaft position sensor:** This sensor detects the position of the crankshaft, and sends a signal to the engine control unit (ECU) when the crankshaft is stopped.
* **Camshaft position sensor:** This sensor detects the position of the camshaft, and sends a signal to the ECU when the camshaft is stopped.
* **Throttle position sensor:** This sensor detects the position of the throttle pedal, and sends a signal to the ECU when the throttle pedal is pressed.
* **Brake pedal position sensor:** This sensor detects the position of the brake pedal, and sends a signal to the ECU when the brake pedal is pressed.
When the car is stopped and the brake pedal is pressed, the ECU will send a signal to the starter motor to turn off the engine. The engine will then remain off until the driver presses the accelerator pedal, at which point the ECU will send a signal to the starter motor to restart the engine.
How Much Fuel Do Stop-Start Engines Save?
The amount of fuel that a stop-start engine can save depends on a number of factors, including:
* **The type of car:** Stop-start engines are more effective in cars with smaller engines and lower weight.
* **The driving conditions:** Stop-start engines can save more fuel in stop-and-go traffic than in highway driving.
* **The driver’s behavior:** Drivers who frequently idle their cars can save more fuel with a stop-start engine.
According to the EPA, stop-start engines can save up to 5% on fuel consumption in city driving. In some cases, stop-start engines can even save up to 10%.
How Much Do Stop-Start Engines Reduce Emissions?
Stop-start engines can also help to reduce emissions, particularly in cities. When a car is idling, it is still producing emissions even though it is not moving. Stop-start engines can help to reduce these emissions by turning off the engine when the car is stopped.
According to the EPA, stop-start engines can reduce CO2 emissions by up to 3%. In some cases, stop-start engines can even reduce CO2 emissions by up to 10%.
Are Stop-Start Engines Worth It?
Whether or not a stop-start engine is worth it depends on a number of factors, including:
* **The cost of the engine:** Stop-start engines are more expensive than traditional engines.
* **The fuel savings:** The amount of fuel that a stop-start engine can save depends on a number of factors, including the type of car, the driving conditions, and the driver’s behavior.
* **The emissions reductions:** Stop-start engines can help to reduce emissions, particularly in cities.
If you drive a lot in stop-and-go traffic and you are concerned about fuel economy and emissions, then a stop-start engine may be a good option for you.
Conclusion
Stop-start engines can help to save fuel and reduce emissions, particularly in cities. The amount of fuel that a stop-start engine can save depends on a number of factors, including the type of car, the driving conditions, and the driver’s behavior. Stop-start engines are more expensive than traditional engines, but they can be worth it if you drive a lot in stop-and-go traffic and you are concerned about fuel economy and emissions.
