Can you use the gears to slow down your car?

Answer 1

Absolutely. You can shift into lower and lower gears to use what is called compression breaking similar to what semi's do going down long hills using a "jake" break. When your foot is not pressing on the accelerator and you go from, just for example, overdrive to drive it increases the RPM's of the engine without supplying it with more air and fuel. This cause the engine to expend more work trying to keep itself rotating that what it generates in the combustion chamber. This will cause your engine to fight against the inertia caused by your car moving thereby slowing down the car. You want to be careful to not shift down to soon or else you may cause excessive damage to your engine. You are better off using the breaks to slow yourself down unless you have no breaks, which if that is the case get it fixed or get a new car.