Can a car stay in S gear on the highway?
2 Answers
Cars should not stay in S gear on the highway. Because using S gear continuously on the highway can damage the vehicle. S gear, also known as the car's sport mode, delays the shifting timing when engaged. This keeps the engine at higher RPMs for longer periods, allowing the car to operate at high RPMs in lower gears to achieve greater output torque. Generally, for automatic transmission cars on the highway, using D gear is sufficient. This is because highway speeds typically range between 90-120 km/h, and with moderate traffic, there's less need for frequent overtaking, rapid acceleration, or hard braking. In such conditions, driving in D gear ensures safer, smoother, and more fuel-efficient operation. S gear is best used when overtaking on the highway. Since overtaking at high speeds requires quick acceleration, engaging S gear provides greater output torque, making the maneuver quicker and safer.
Using the S mode continuously on the highway is certainly possible, but based on personal experience, it's not ideal. The S mode is designed to keep the engine RPM in a higher range, which indeed provides faster acceleration response—making overtaking thrilling. However, fuel consumption increases significantly in this mode compared to driving in D mode, leading to higher fuel costs. Moreover, maintaining high engine RPM for extended periods at steady highway speeds may accelerate wear on components like the transmission or pistons, increasing maintenance costs. When driving on the highway, I prefer using D mode for its smoothness, fuel efficiency, and lower noise. I only switch to S mode occasionally for quick acceleration when overtaking, then switch back immediately afterward. This approach protects the car and saves money, making long-distance driving more worry-free.
