Is it okay to use S mode continuously at high speeds?
2 Answers
It is not recommended to use S mode for extended periods during high-speed driving. This is because S mode only delays upshifting without altering other operational aspects, which inevitably increases the transmission load in the short term, raises temperatures, and accelerates wear. Additionally, vehicle comfort is slightly reduced in S mode, so prolonged use should be avoided. Due to its stronger power output, S mode is typically engaged for overtaking or climbing hills, after which it is advisable to switch back to the more economical D mode. From a fuel consumption perspective, S mode consumes significantly more fuel than normal mode because of increased fuel injection at higher RPMs, and it also tends to wear the transmission more. Therefore, it is unnecessary for everyday driving. S mode is the car's sport mode. When shifted into S mode, the transmission can change gears freely, but the shifting timing is delayed, keeping the engine at higher RPMs for longer periods. This allows the car to maintain lower gears at higher RPMs for extended durations, resulting in greater torque output and acceleration.
When I drove an automatic transmission car on the highway, I tried using the S mode for a long time. At first, I felt the acceleration response was quite fast, making overtaking more powerful, and the engine sound also had a sportier feel. However, I soon noticed a significant increase in fuel consumption—after driving a few hundred kilometers, the fuel gauge dropped nearly a full segment, and the noise was too loud, making my ears uncomfortable during long drives. I checked the car's manual and found that the S mode is intended for scenarios requiring extra power, such as mountain roads or rapid acceleration, not designed for highway cruising. When maintaining a steady speed within the speed limit on the highway, the D mode's shifting logic is smoother and more economical. Keeping it in S mode all the time offers little practical benefit beyond some extra driving fun, while costing more in fuel and potentially accelerating engine wear. Now, I only switch to S mode when overtaking and return to D mode afterward.
