2006 Pt Cruiser will not start but battery and alternator less then a year old

My granddaughter presently has the same problem. I am not sure about the MPG but I noticed quite a few videos on the ignition switch actuator and how to replace. It seems to be a solution for that particular problem. Very expensive to have done at the dealers but you might research that.

Could be the Starter Solenoid, or the Starter. They require the most CCA. Starter Solenoid costs less, a new starter can come with or without a new Solenoid. Either way you would need to remove the starter to change the Solenoid. The starter could be sticking causing the vehicle to draw more CCA, Therefore-needing a jump. A lot of draining CCA's in any of these situations.