Trying to get back into Automation, my cars have never been able to get that high mileage. This is for several reasons, including my own lack of skill. However, the two biggest ones are that I tend to have either a monstrous stereotypical American giant engine, or a stereotypical European displacement-tax dodging engine that revs like crazy to squeeze every last kilowatt out of its small frame.
Neither is conducive to fuel economy.
My own tendency to go to extremes exacerbates the problem. If not that, it’s a small city car engine. Even then, I tend to rev it to maximum power to get every last drop of-you see where this is going.