Because the engine provides the power to operate the drivetrain, which is what makes the car move in the first place. Turn the engine off, and there is no more power going to the drivetrain - the remaining movement of the car until it stops is simply inertia.
When a car is switched off, the engine stops running and there is no longer any power being generated to maintain the car's speed. Without the engine running, there is no energy being produced to keep the car moving, so it slows down due to the forces of friction and air resistance.
Could be but probably an engine problem.
TPS sensor or maf. I seafoamed my entire car seemed to do the trick
That is normally caused by an air leak in the induction system.
Gravity
A parachute.
A car goes faster when you accelerate. It slows down when you brake.
Friction between the tires and the road surface can slow down a car going down a ramp. The brakes can also be applied to introduce additional friction and slow the car further. Additionally, aerodynamic drag can play a minor role in slowing down the car at higher speeds.
The main factor that causes the motion of a car to slow down as it moves up a slope is gravity. Gravity acts in the opposite direction to the car's motion, pulling it back down the slope. This force opposes the car's forward movement, making it slow down.
your car needs a tuneup,plugs,air filter. should do it
Are you going up a hill? Did you take your foot off the gas and is the compression of the engine slowing you down? Are your brakes sticking? Is your car getting the correct amount of air to fuel ratio? there are lots of reasons why a car would slow down while you're driving it. start with the easiest.
By far the best method to slow down is to look at the road ahead to work out if you need to slow down, and then to back off the accelerator (gas pedal) and let the car slow naturally so that you arrive at the next bend/junction (or whatever) without actually having to use the brakes or down-shift at all.Otherwise, use the brakes, they are cheaper and easier to replace when they wear out than the engine/transmission.