1. Idling. Your car isn't going anywhere but the motor spins and burns gas anyway, it can't rest, it cant stop. 2. Tailpipes. ICEs are so inefficient that they need to constantly spew heated gas out. 3. Catalytic converters. You've got a big tank full of expensive fuel, but you don't completely burn it - so this thing finishes the job. 4. Mufflers. Make a ton of noise so carry around a heavy chunk of metal to quiet it down. 5. Oil filters. Normal operation is constant grinding, so this thing collects all the filings. You didn't need those filings anyway. 6. Brakes. Every time you slow down you grind one surface against the other instead of reclaiming the kinetic energy to use again. Stupid. 7. Transmissions. Efficiency band is so narrow that you have to have a big mess of gears to constantly change. Added complexity. 8. Starter motors. This exact same thing just scaled up could move the car all by itself. 9. Spark plugs. They wear out and need to be replaced! 10. Oil changes.