Does keeping autohold on consume more fuel?
3 Answers
Keeping autohold on does consume more fuel. However, staying in D gear and pressing the brake for a long time will increase the temperature of the transmission oil, making it prone to deterioration and aging. Here are the specific details: 1. Introduction: The English name for automatic parking is AUTOHOLD, which is a function that automatically replaces the handbrake. 2. Applicability: After activating this function, for example, when stopping at a traffic light, it is equivalent to not having to pull the handbrake. This function is particularly suitable for uphill and downhill driving as well as frequent starting and stopping. It simplifies operations by avoiding the use of the handbrake or electronic handbrake, and automatic transmission models do not need to frequently switch between D to N or D to P.
I often use the autohold function when driving myself, and after using it for over three years, I found that it doesn’t consume extra fuel at all. The principle is simple: autohold just automatically applies the brakes when the car is stopped, keeping it stationary. At this point, the engine is still idling normally, consuming the same amount of fuel as when in neutral with the handbrake engaged. When starting off, a slight press on the accelerator releases it without extra fuel injection. On the contrary, it’s especially practical in city traffic jams, saving you from constantly pressing the brake pedal and getting tired. Many people worry that auto start-stop consumes fuel, but autohold is a completely different thing. My actual fuel consumption data shows no significant difference between having it on or off over the long term. The key factor affecting fuel consumption is driving habits, such as aggressive acceleration or sudden braking, which consume more fuel. So, there’s really no need to turn off autohold just to save a tiny bit of fuel—convenience and comfort are more important.
I've studied automotive electronic systems, and in theory, having autohold on does not increase fuel consumption. Its working principle relies on the ESP system's hydraulic pump to maintain brake pressure, which consumes the battery's electricity, while the alternator's power generation burden is minimal, having almost no impact on the engine load. For example, when waiting at a red light with autohold on, the engine's idle fuel consumption is about 1 liter per hour, which is exactly the same as when you manually press the brake. Of course, when starting on a slope, a bit more throttle might be needed to counteract gravity, but this incremental increase is negligible. On the contrary, its greatest value lies in reducing operational burden and preventing rollback accidents, making it particularly suitable for urban driving conditions. As long as the brake system is regularly checked to prevent brake drag from increasing resistance, there will be no change in fuel consumption.
