What gear should be used for automatic transmission cars on highways?
2 Answers
When driving on highways with an automatic transmission, use the D (Drive) gear. Automatic transmission cars do not require the driver to manually shift gears; simply keeping the gear in D allows the car to automatically change gears based on the current speed. If you need to overtake, maintaining high engine RPM is necessary, and in this case, the S (Sport) gear can be used. While driving at high speeds, it is important to control the vehicle's speed and avoid exceeding speed limits. Automatic transmission generally refers to a car's automatic gear-shifting mechanism, where the transmission control system selects the appropriate gear based on the engine's RPM and load, replacing the driver's subjective judgment and manual gear-shifting operations. A typical automatic transmission car has six gear positions, arranged from top to bottom as: P (Park), R (Reverse), N (Neutral), D (Drive), S (Sport), and L (Low).
For daily highway commuting, I mostly use the D gear and keep the cruise control on for convenience. As long as the road conditions are smooth, I let it control the speed automatically, and the buttons on the steering wheel make adjusting the speed very easy. Maintaining the RPM around 2000 in flat areas is the most economical—I once drove over 700 kilometers on a single tank of fuel during a long trip. If encountering continuous uphill or downhill sections, I switch to manual mode and lock it in 6th gear to avoid frequent gear shifts. Modern automatic transmissions are quite intelligently tuned, and unless you need to overtake frequently and briefly use the S gear, there's really no need to fiddle with the gears unnecessarily. Remember to wait two or three seconds after each gear shift to allow the transmission to fully engage—forcing the throttle aggressively can cause jerking. Keeping it in D gear on the highway is both worry-free and safe.
