Does Turning Off the Engine Save Fuel or Keeping It Running?

[SimonDella]

Turning off the engine when parked saves more fuel than keeping it running. This is because a car consumes fuel when idling but not when the engine is off. Relevant details are as follows: 1. Traffic Lights: When waiting at a traffic light, you should judge the parking time based on the traffic signal timer. If the waiting time exceeds 1 minute, it is advisable to turn off the engine. Generally, the fuel consumed by idling a small car is more than the fuel required for a restart. 2. Lifespan: The engines of typical household cars are usually designed to withstand over 50,000 starts. Given the frequency of turning off the engine during parking in regular use, even after 10 years, the number of starts would still be far below 50,000. Therefore, reasonable engine shutdown during parking will not adversely affect the vehicle's engine or battery.

[McDonovan]

Having driven for decades, my experience tells me that turning off the engine when parking usually saves fuel, because idling can consume half a liter to one liter of fuel per hour—it's like burning money for nothing. Turning off the engine at red lights or during short stops exceeding 30 seconds adds up to significant savings over time. However, frequent starts can be harsh on older engines, increasing wear on the starter. Modern cars come with auto start-stop technology, making engine shutdowns and restarts smoother, which doesn’t harm the vehicle and reduces consumption. I’ve found that sticking to this habit long-term can save me ten or twenty bucks on fuel each month, while also benefiting the environment by reducing exhaust emissions. Of course, in cold weather or for stops lasting just a few seconds, it’s better not to turn off the engine to avoid the extra fuel cost of restarting. Overall, applying this strategy reasonably delivers good fuel-saving results.

[Sawyer]

I prioritize environmental protection and daily savings, making engine shutdown my go-to strategy. Idling not only wastes fuel but also increases pollution. I manually turn off the engine or rely on the auto start-stop system whenever stopping for more than a minute or two, which noticeably saves fuel. Modern technology has made the startup process more efficient—while instantaneous fuel consumption may spike slightly, the long-term savings are significant. I've kept track, and the fuel saved in a year covers several short trips. This approach is especially effective in congested urban driving, where frequent stops make idling wasteful. Once it becomes a habit, the operation feels natural, causes no harm to the vehicle, and supports green mobility. Concerns about battery and starter wear are overstated; with reasonable use, the benefits far outweigh the minor risks.

[DelTheo]

Does turning off the engine save fuel? From a driving habit perspective: turn off for short stops, keep running for long stops. Idling consumes a lot of fuel—stopping for even a minute can waste gas, and turning off immediately cuts losses. However, the momentary fuel consumption during startup is slightly higher, and frequent operation may accelerate component wear. In practice, I only turn off the engine for stops over 30 seconds, achieving noticeable fuel savings without overburdening the car. If the vehicle has an auto start-stop feature, just use it—no manual hassle and it's safe. This method is simple and effective, so I recommend giving it a try.