What gear should an automatic car be in when going downhill?

[GenesisLynn]

L1 or L2 gear. The following is an introduction about L gear: 1. L gear: L gear is the low gear, which limits speed. When this gear is engaged while going uphill, it maintains a state of high RPM and low gear, thereby keeping the car full of power. When engaged while going downhill, it also prevents the car from accelerating excessively. The English for L gear is LOW, meaning low speed or slow speed, so L gear is the low forward gear. Generally, only mid-to-low-end automatic transmission models have L gear, because these models' automatic transmissions do not have a manual mode. Shifting from D gear to L gear does not require stopping or braking; you can push the gear lever into L gear while driving. Once L gear is engaged, the transmission will only switch between 1st and 2nd gears, and no matter how much you press the accelerator, it will not shift to 3rd gear or above. 2. L1, L2 gears: Some models on the market may have L1, L2, etc. marked on the L gear, corresponding to the restricted gears. The vehicle will not shift above the restricted gear, but can only engage these gears at sufficiently slow speeds; otherwise, the transmission will not respond to the gear-shifting operation.

[DiClayton]

When driving an automatic car downhill, I'm used to shifting to a lower gear, like L gear or manually downshifting to 2nd or 3rd gear. This mainly relies on the engine to control the speed and prevents overheating the brake pads from prolonged braking. I remember last year when driving down the long slopes of the Sichuan-Tibet line, there was a continuous 20-kilometer descent. If I had only used D gear and relied on the brakes, they probably would have been smoking by now. The specific operation is to slow down before the descent and directly shift to a lower gear. The RPM will rise, but don't worry—the engine noise getting louder is normal. If the car has a hill descent control function, it's even easier—just press the button and the system will automatically control the speed. After descending, remember to shift back to D gear promptly to avoid prolonged high-RPM operation of the engine.

[DeReese]

The most important thing when driving an automatic transmission downhill is speed control. I choose the gear based on the length of the slope. For short slopes, using D gear with intermittent braking is fine, but for long slopes over three kilometers, switching to a lower gear is essential. The principle is simple: let the engine act as a natural brake—the higher the RPM, the stronger the engine braking effect. Once, while driving a friend's car on a mountain road, his model with paddle shifters was particularly convenient. I simply downshifted two gears using the paddles while keeping my right hand on the steering wheel. It's important to monitor the dashboard—if the transmission warning light comes on, it indicates improper gear matching. For extremely steep slopes, you can use the M (manual) mode to lock in a gear. I often use 2nd gear, which keeps the speed around 30 km/h without needing to brake at all.

[EmersonAnn]

For automatic transmission vehicles, gear selection during downhill driving depends on the situation. For regular cars, I directly switch to L (Low) or S (Sport) mode, both of which are low-speed settings. The key point is to never coast in N (Neutral) gear - it damages the transmission and is dangerous. On steep slopes, after shifting to lower gear, you'll clearly feel the vehicle being held back, and only light brake pressure is needed. I remember driving a rented SUV to Huangshan last year - many cars had their brake lights constantly illuminated on continuous downhill sections because they didn't use low gear. Many new cars now come with grade sensing functionality that automatically downshifts during descents. The core principle is to let the engine assist in braking, not relying solely on the brake system. For short slopes, don't overthink it - D (Drive) mode with moderate braking is perfectly sufficient.

[OmarAnn]

When driving an automatic transmission car downhill, I usually handle it this way: first slow down to a safe speed, then switch to manual mode and downshift. Generally, shifting to 3rd gear is sufficient for small slopes, while steep slopes require downshifting to 2nd or even 1st gear. The principle is to use the engine's compression resistance to control speed, which can double the lifespan of the brake pads. Once on the highway, I encountered a long downhill and preemptively shifted to M2. A truck driver behind me flashed his lights to warn me I was going too slow, but by the bottom of the slope, his brakes were smoking. A special reminder for turbocharged cars: when in low gear at high RPM, the turbo can suddenly kick in and accelerate the car, so it's advisable to keep the RPM below 2,500. If the speed increases during the descent, lightly apply the brakes first before downshifting further.

[DiBeckett]

When driving an automatic transmission car down a long slope, I never keep it in D gear and rely solely on the brakes. The reliable method is to shift into L gear or a lower gear in manual mode, allowing the engine to assist with braking. Specific operation: Before descending, reduce the speed to below 40 km/h, then use the right hand to shift the gear lever into the low-speed range. At this point, the tachometer needle will suddenly rise, indicating that the engine is providing braking force. Two years ago, when driving a commercial vehicle to Zhangjiajie on a 20-kilometer continuous downhill, I kept it in M2 gear, and the brake pad temperature never exceeded the warning line. Some models don't have a dedicated low gear, so you can use S gear instead. The key point is not to shift up too late; when you see the slope becoming gentler, adjust to a higher gear in time, otherwise the engine roaring will consume too much fuel.