What “true cost” includes
The advertised payment is standard amortization: principal after down payment, monthly rate r = APR / 12, term n months:
PMT = L · r · (1 + r)ⁿ / ((1 + r)ⁿ − 1)
Fuel is (miles per year ÷ MPG) × gas price, spread over 12 months. Insurance, maintenance, and registration are cash costs. Depreciation is not a bill, but it is a cost: the calculator takes your annual depreciation rate and spreads the first-year dollar loss across months, and compounds that rate over five years for the long-haul total.
New cars often lose ~15–20% in year one. Used cars depreciate slower but bring higher maintenance. Either way, a $400 payment wrapping a $1,100 true cost is a FIRE leak: $1,100 a month is $13,200 a year, which is $330,000 of required portfolio at a 4% withdrawal rate.
Figures are illustrations. Your insurance quote, commute, and residual value will differ. Use the sliders until the bar chart matches the car you are actually considering.