I’m mostly thinking about a scenario where you are going down a highway (say, at 120kmh for the sake of the example) and suddenly your brakes fail
could shifting to Reverse function as a brake in that situation?
edit: thank you all for the answers, I want to note that I myself don’t drive and did not consider doing this, I was just wondering if this was possible
have a lovely day o/
In: 11
No you can not shift into reverse to stop the vehicle, pretty much every single vehicle on the road is going to have some sort of a fail safe to keep you from doing so because it would simply destroy the transmission and provide 0 benefit in any situation. The reasoning is because it would just sheer the teeth right off the gears because the wheels would be trying to go from 120km/h in one direction to the opposite direction instantly.
Now the scary part is no one here gave good advice in what one should do in a situation like this. Now surprisingly manual or automatic, the procedure is essentially the same (although a manual has a few more steps). In an manual transmission you shift down from 5->4->3->2->1 with 0 input on the throttle. The centripetal force of the engine spinning without the assistance of the throttle works as a braking system (not nearly as good as regular brakes). It’s simply called engine braking and something people that drive a manual transmission often do to conserve their brakes. Now in an automatic transmission you don’t have the same level of control because the transmission does its own shifting, but this also makes it a bit easier. As soon as you realize your brakes are not working you can take your gear shifter and shift it into L (for low) or 1 depending on how your transmission is labeled. This will have a similar effect of downshifting like a manual transmission, except it will go from gear to gear on its own as your speed is reduced to not cause damage to the vehicle and work as intended. A lot of people don’t understand that an automatic transmission is still capable of this. Doing this will greatly reduce your speed and could save your life.
The other important thing to do is to apply your emergency/parking brake, hence why it’s named the “emergency brake”. Now it’s important to note that this brake does not share the same safety features of your standard brakes. If you apply this brake 100% your vehicle is likely to skid and increase the odds of getting in an accident. You want to gently apply the emergency brakes and keep applying pressure making sure you don’t make the tires chirp. If you act quickly doing both of these things you can bring your vehicle to a stop in a short distance and safely. It could be what saves your life.
Just in the spirit of ELI5: When talking about the engine braking I’ll explain it a little more so it may makes sense how it works better. We all know that an engine uses fuel to make it function, the fuel is the energy used to make the pistons go up and down and the crankshaft spin which spins the transmission which spins the tires. Now lets say you are cruising in your vehicle and are doing 100 km/h with the engine spinning at 4,000 RPMS (revolutions per minute), which you normally wouldn’t do but its a theoretical for this example. Now if you were to stop providing fuel and air to the engine through the throttle, the engine wouldn’t simply stop spinning immediately. What would happen though is instead of the engine providing thrust to the transmission spinning the tires, it would work like an anchor and the energy to spin the engine would come from the vehicle’s motion forward. This is going to cause the vehicle to slow down because the forward momentum is being sapped by the spinning of the engine without the use of fuel.
Latest Answers