I just purchased a 2016 Passion. I parked at work a bit early to spend time getting to know the car. I'm sitting in 'Park' and realize how loud the engine noise is, a roaring almost. I shut off the a/c to see if that was causing it. I don't think there was much difference. Having only purchased it the previous late evening, I've had little time to figure things out. Later, at my break, I came out, restarted engine to sit for my 15 minutes. The loudness didn't start immediately. Can anyone tell me what I did that I shouldn't have? When I parked the car after having driven it 15 minutes from home, did I leave something running that I should have manually turned off? I'm quite puzzled. I also noticed that what little display is showing, (I haven't had time to organize computer readouts...) showed, as I sat idling, a definite drop in mpg. It just kept dropping and dropping. Was the engine running too, (I don't know what to call it..) high??? If someone understands what I'm concerned about, love to hear from you and thank you!!