Will the Car Stall When Braking from 4th Gear to 20 mph?

[MacZachary]

Generally, it won't stall, but if you keep the clutch partially engaged while braking to a stop, the car may stall. In any gear (except neutral), if the car comes to a complete stop without pressing the clutch, it will stall. Here is some relevant information: When the gear is in 1st to 5th: If the clutch is not pressed and the speed starts to decrease, the car will stall when the speed drops to a certain point. Additionally, water in the exhaust pipe, engine failure, or running out of fuel can also cause stalling. If the gear is still engaged: Stalling due to not pressing the clutch can damage the car. Forcing the gear shift without fully pressing the clutch can also lead to stalling and may cause the gear teeth to break. Broken gear teeth can result in frequent gear disengagement in the future.

[StTeagan]

I've been driving manual transmission for over a decade, and this situation is indeed prone to stalling. When you decelerate to 20 mph in 4th gear, the engine RPM drops too low, especially in higher gears where the idle point is typically around 700-900 RPM. If you're going slow and also applying brake pressure, the engine can't keep turning and will stall directly. This isn't just dangerous—it makes the steering wheel stiff, reduces brake assist, and could cause an accident. I recommend developing a deceleration habit: as soon as you see your speed dropping, press the clutch to disengage the power, then downshift to 2nd or 3rd gear to restart. I've tried ignoring this step in city traffic congestion before, and the car stalled completely, costing me money in repairs. Remember, higher gears are for high speeds—you need to use lower gears to maintain RPM at low speeds so the engine can handle it.

[AsherRose]

I've experienced this myself—when slowing down in a manual transmission car, never linger in a high gear. For example, dropping from 4th gear to 20 mph without downshifting can cause the engine RPM to lag, placing excessive load on the engine when braking, potentially leading to an instant stall. The reason is simple: a car engine is like running—if you sprint too fast and suddenly try to walk slowly without adjusting your posture, how could you sustain it? My advice is to always check the speedometer before decelerating. Once the speed drops, immediately press the clutch pedal to prevent engine shutdown. Doing this long-term can also damage spark plugs or transmission components, so it's crucial to inspect the idle system and clutch wear during routine maintenance. Don’t underestimate it—my neighbor’s car ended up in the repair shop with hefty bills due to a similar issue.

[SanMarley]

A manual transmission car can indeed stall when slowing down to 20 mph in 4th gear because the engine speed is too low to sustain the load. The solution is simple: depress the clutch pedal during deceleration to cut off power transmission, or downshift to an appropriate gear like 3rd gear in advance. This avoids the risk of engine stalling, including reduced braking efficiency and loss of steering control. It is recommended to always pay attention to the matching of speed and gear while driving, and use lower gears more frequently at low speeds. Practicing a few times will help develop this good habit.

[LaMaggie]

Frequently operating this way not only makes stalling likely but also harms the engine. Braking while driving at 20 mph in 4th gear forces the engine to endure high pressure at low RPM, potentially causing carbon buildup or premature component wear. To prevent stalling, always depress the clutch or downshift when decelerating. From personal experience, regular maintenance like idle speed adjustment and clutch hydraulic system checks can minimize such issues. Safety first - restarting after stalling is troublesome and disrupts trip smoothness.