Can the S gear of an automatic transmission be used continuously on highways?
3 Answers
Automatic transmission S gear should not be used continuously on highways. The S gear only delays upshifting without changing other working conditions, which will cause the transmission to bear increased load in a short time, leading to higher temperature and accelerated wear. An automatic transmission does not require the driver to shift gears manually; the vehicle will automatically select the appropriate gear based on driving speed and traffic conditions. The gears of an automatic transmission are: 1. P gear is the parking gear and starting gear; 2. R gear is the reverse gear; 3. N gear is the neutral gear; 4. D gear is the forward gear, also known as the driving gear; 5. L gear is the low-speed gear; 6. OD gear is the overdrive gear.
When I used to drive an automatic transmission car, I often used the S mode on highways and found it fine in the short term, providing a more exhilarating acceleration experience. However, it's not ideal for long-term use. The S mode is a sport mode, which delays gear shifts and keeps the engine RPM at a higher level, delivering powerful acceleration when overtaking on highways. But driving continuously for several hours increases engine load, significantly raising fuel consumption. The SUV I drove consumed about 15% more fuel in S mode compared to normal D mode on highways, which isn't wallet-friendly. Additionally, high RPMs accelerate wear and tear on components, such as pistons and bearings, which can overheat and shorten their lifespan. It's advisable to switch to S mode only when extra power is needed, like during uphill or downhill driving or overtaking, and return to D mode for smoother operation otherwise. Remember, regular vehicle fluid checks can prevent unexpected issues.
I often drive long distances on highways and tried keeping the car in Sport (S) mode continuously. The result was noticeably louder engine noise, with RPMs consistently hovering above 5,000. While theoretically drivable, this poses safety risks—the engine temperature rises too quickly, potentially affecting braking and handling responsiveness, especially during emergency maneuvers where reactions may lag. This mode is designed for short-term power boosts, not extended highway cruising. If you insist on using it, I recommend taking more frequent breaks at highway service areas to let the engine cool down and prevent driver fatigue. Maintain a steady speed between 80-100 km/h and avoid aggressive throttle inputs to reduce mechanical strain. Occasional S-mode use is fine, but for highway cruising, Eco or standard Drive (D) modes offer more reliable and safer operation.
