I thought that was so high, so I ran the numbers using some median and average values and I got pretty close.

The average vehicle costs $40k, is owned for 11 years, gets driven 13k miles per year, burns 25 mpg, gas costs $3/gal, insurance is $1500 per year, and the vehicle needs $900 per year in maintenance and repairs.

A lot of people spend far less than this (my car cost me $0.384/mile so far), and some spend far more, but it's not a bad approximation.

Businesses generally are allowed to depreciate automobiles over five years, and you might guess it is because they get a fairly high amount of use.

And built into the IRS rate is probably an expectation of significant repairs.

That changes the capital costs.

Most people are paying 4.00 to 5.00 dollars a gallon these days.

At a generous $4.00 a gallon, and as you indicate, .04 gallons per mile, gas alone is lately above 0.16 cents a mile. At $5, that would be 0.20 cents.

Generously (on the thrifty side) estimating, at minimum, capital, insurance and maintenance doubles cost of gasoline alone.