What is the most fuel-efficient speed for a 4AT transmission?
2 Answers
Fuel efficiency is not significantly related to speed or the type and structure of the transmission. The key to saving fuel lies in controlling the engine's RPM. Here are the details: 1. On highways: If driving on a highway, maintaining a constant speed, such as around 110 km/h, and avoiding braking and sudden acceleration can help save fuel, as these actions may cause RPM fluctuations. 2. Engine RPM: For a 4AT transmission, these fluctuations become very noticeable. To achieve better fuel efficiency with a 4AT, the secret is to keep the engine RPM as stable as possible. The engine's RPM is the most critical factor affecting fuel consumption.
I've been driving for decades and have experience with many 4-speed automatic transmission vehicles. The most fuel-efficient speed seems to be maintaining between 60 to 70 kilometers per hour. At this range, the engine runs smoothly, the transmission is in top gear, and the engine RPM remains low, resulting in significantly reduced fuel consumption. This speed range works best for suburban roads or highway entrance sections. When driving too fast, like at 100 km/h, wind resistance increases dramatically and fuel consumption spikes. Similarly, driving too slow at around 30 km/h with frequent acceleration/deceleration and gear changes also wastes fuel. I remember a trip two years ago - by maintaining a steady 65 km/h, I got an extra 50+ kilometers from a full tank. Regular transmission fluid changes during maintenance can also optimize fuel efficiency. Overall, finding your vehicle's optimal cruising speed is crucial.