During a slow snowy weekend I finally spreadsheeted three years of
Honda bills
and came up with about 20 cents a mile operating cost for my civic
(40K miles).
That includes gasoline, maintenance, insurance, but not depreciation.
My 1990 average 11 cents a mile over its lifetime, when gas was
cheaper.
Insurance hasnt changed that much over the decades.  Age discounts
tend to counteract inflation.
Its was very short spreadsheet.  Besides the seven periodic
maintenances,
there was failed pollution sensor (warranty) and new winter tires.
Not much.