[Chrysler kid]

Most likely if you are using the starter to start the car it's using more energy than it is saving.

For bump starting I have always used third gear. If you ever have a dead battery or dead starter you must drop the clutch in third to get the vehicle running.

What I've always heard is that it takes more fuel to start the car than to let it idle, which was especially true in my camaro which puffs gasoline out of the tailpipe when it starts on a cold day. All of the emissions systems are removed but yeah.