Yes, you can save a "few" bucks by cutting corners. Such as not having collision/theft insurance. Or by not driving as much. Or by purchasing more cheaply (good luck on that one by the way)
However, Edmund's is fairly accurate given the constraints.
I "rant" about "cost per mile" all the time. People will SWEAR up and down that I am wrong. But, I'm here to tell you that driving a car ain't free. People argue with me that they drive more cheaply because they purchased "used" at a bargain. But they fail to take into account all the predictable future costs. Used cars, even lightly used cars don't save much money per mile. When all the other mandatory costs and factors are added in.
My co-worker insists on driving older Camry's that he purchases "cheap" because they are reliable cars. One $2000 transmission, a $1000 brake job, an expensive failed ABS unit, 3 in tank fuel pumps, a radiator, a hose set, 2 alternators, a gaggle of oxygen sensors, multiple cheap tire sets, less than ideal fuel economy, and near zero value when he is done with them add up to about 55cents per mile driven. He will NEVER get it.... None of his cars have made the magic 250,000 mile mark without massive expense. And, guess what? It's dead right now!
He really could drive a reliable brand new car for that kind of cost.