Should I use M+ or M- when going uphill in M mode?

[McLouis]

You should use M- when driving uphill. The M mode is the manual mode of an automatic transmission. When engaged in this mode, you can upshift at high speeds and downshift at low speeds. Other gear positions of an automatic transmission include P, R, N, D, etc. Here is some relevant information about automatic transmissions: Introduction: As the name suggests, an automatic transmission does not require the driver to manually shift gears. The vehicle will automatically select the appropriate gear based on driving speed and traffic conditions. Generally, there are six gear positions in an automatic transmission car, from top to bottom: P, R, N, D, S, L. Working principle: The engine's power is transmitted through the gearbox, which is also a key factor affecting fuel consumption. Generally, automatic transmissions consume over 10% more fuel than manual transmissions. Whether manual or automatic, the more gears a transmission has, the more fuel-efficient it is.

[CollinRose]

Recently, I’ve been driving a lot on mountain roads and have gained plenty of experience using the M mode for uphill climbs. Uphill driving requires more torque, so higher RPMs are necessary. In this case, shifting down with M- gives the car more power. Once, I accidentally shifted up with M+ on a steep slope, and the car immediately lost power—the engine groaned and struggled to climb. After switching to M- and downshifting, the RPMs rose, and the throttle response became noticeably quicker. Remember, the lower the gear number, the more power you get—for example, dropping from M4 to M3 or even M2 is especially helpful. Downshifting early is also crucial; shift into the right gear as soon as you see the slope, don’t wait until you’re halfway up. If the slope is extremely steep, you can even drop to 1st gear. If you feel the power isn’t enough mid-climb, you can continue downshifting—it’s a straightforward process.

[JaxonMarie]

Speaking as an experienced driver, here's the thing. When using M mode for uphill driving, you definitely want to select M- for downshifting. The principle is simple: lower gears provide higher torque, giving you more power for climbing. Once when I was driving a friend's car up a winding mountain road, he suggested I try M mode, so I kept my eyes on the tachometer. When I used M+ to upshift, the RPM immediately dropped, and stepping on the gas pedal had no effect. But after using M-, the RPM climbed above 2,500, and I could clearly feel the increased traction. My advice is to downshift at the base of the hill - shifting halfway up can cause jerking. Keep an eye on the tachometer needle; if it drops below 2,000 RPM, it's time to downshift. You can adjust gears flexibly for different slopes: drop 1-2 gears for steep inclines, while 3rd gear may suffice for gentler slopes.

[LaRose]

Last year when I just learned to use manual mode, I also struggled with this. Now I've figured it out. You must downshift (M-) when going uphill! I had an embarrassing experience: as a beginner, I once upshifted (M+) on a slope, and the car just shook and couldn't climb, with horns blaring behind me. The instructor immediately pointed out the issue: upshifting (M+) reduces RPM and weakens power, while downshifting (M-) gives the engine more strength. Now I always downshift to M2 in advance when climbing, or directly to M1 for steep slopes. Listen to the engine sound during operation: if you hear it struggling, it's time to downshift. Actually, automatic transmissions follow the same logic by downshifting automatically when climbing - we're just doing it more decisively with manual control. Don't worry about fuel consumption; short periods in lower gears won't harm the car.