You can add engine wear but the reading on the odometer will not change since the sensor for the odometer is located at the output end of the transmission or transaxle, and therefore only gives a reading when the vehicle is moving (or when the wheels are spinning, if you are on ice or up on a hoist).
So, no, you will not add mileage by idling.
Effectively all the fuel that it burns while idling. You are getting 0 miles per gallon while idling.
I sat in my car in the driveway with the car idling, waiting for the kids to come out.
The same on a car equipped with manual transmission. On an automatic equipped car it will use less idling.
Idling is what your car is doing when it is just sitting somewhere running. As soon as you press on the gas it is no longer idling. Your idle speed is the number of RPMs your engine runs at when you are idling.
It depends on how long you are idling, or how fast you are going. If you know you are going to be idling for a long time, it's best just to put your car in park.
If a car shakes and loses power when idling it can be the spark plug. If a spark plug is fouling, it can cause power losses.
moving
by the idling air control valve
A car that is stopped with the engine running.
Check the thermostat and replace if you have more than 30,000 miles on it They sometimes stick partially closed and cause overheating. A second cause may be a clogged or undersized radiator. You can have a radiator shop clean it or better yet, have them build a new radiator but add an extra row of coils to add extra cooling.
high miles, try going to auto zone and getting some stop smoke, it's an oil aditive
If the car dies while idling, the timing might be off. Other causes can include a clogged fuel filter or a bad spark plug.