Is the vehicle resistance greater or smaller on a downhill slope?

[ElisaLynn]

On a downhill slope, the vehicle resistance is smaller compared to a flat road. Due to the effect of gravity, the driving resistance is reduced, making it easier for the vehicle to speed up. As a result, the vehicle becomes harder to control than on flat ground, so overtaking should be avoided on downhill slopes. Here is an extended explanation: 1. Vehicle driving resistance: This refers to the resistance encountered by the vehicle during movement, including air resistance, rolling resistance, gradient resistance, and acceleration resistance. Among these, rolling resistance and air resistance exist under all driving conditions, while gradient resistance and acceleration resistance only occur under certain driving conditions. 2. Increase in vehicle driving resistance: This is when the vehicle feels underpowered during movement, the speed does not match the gear, and fuel consumption increases. On straight and flat roads, the coasting performance deteriorates when the vehicle is in neutral gear.

[LaAlivia]

On downhill sections, I feel the vehicle's resistance indeed decreases. When I drive myself, often on mountain roads, I can clearly feel the car glides smoothly downhill, almost without needing to press the accelerator—it just rolls down on its own. This is because gravity helps pull the car downward, unlike uphill where you have to fight against gravity, wasting fuel and effort. However, with reduced resistance, the car tends to speed up more easily, which isn’t a good thing. I’ve experienced situations where the brakes overheated, so it’s crucial to slow down in advance. For manual transmission cars, shifting to a lower gear helps control speed more safely. It’s similar to riding a bike downhill—just a light brake touch is enough to manage, saving a lot of effort. Overall, reduced resistance downhill saves fuel, but drivers must stay alert to avoid unintended acceleration and accidents.

[TaliaLee]

From my experience in car repair, the resistance of a vehicle is relatively small when going downhill. The force of gravity allows it to naturally descend, reducing the burden on the engine. Lower resistance means less energy consumption, which can also save some fuel. However, don't be fooled by this advantage—rolling resistance and air resistance still exist, they're just less noticeable with the assistance of the slope. The key reminder is that with reduced resistance, tires are more prone to slipping, especially in rainy conditions, requiring the braking system to work more frequently. I recommend switching to engine braking mode in advance on steep slopes for better safety and efficiency.

[AllieDella]

As someone who enjoys studying automotive operating principles, the resistance a car encounters when going downhill is certainly reduced. Gravity pulls downward, acting like an invisible helper that allows the car to glide smoothly. But don't overlook the everyday risks—with reduced resistance, speed can surge rapidly, increasing braking distance. Imagine what would happen during emergency braking? Component wear accelerates, which is why I always teach beginners to practice anticipatory driving rather than just focusing on fuel-saving fun.

[VanCourtney]

On downhill sections, I've noticed that the vehicle's resistance generally decreases. This is particularly noticeable during high-speed cruising, where the car runs smoothly with improved fuel efficiency, especially on long descents. The benefit of reduced resistance is better economy, but the downside is increased pressure on the control systems. I often recommend checking brake pads and tire conditions to avoid complacency due to effortless coasting. Remembering these small details can make the journey safer.