August 2026
A short walkthrough of the product comparison, editable assumptions and five-year total-cost result.
A car’s price is obvious. Its cost is not.
I am analytical enough that buying a car immediately produced a list of conditions. When does a used car make more sense than a new one? At what mileage does petrol become more expensive than an EV? How much should I value a better finance offer, a longer warranty, lower servicing costs or an uncertain resale value?
My personal context made the usual comparison incomplete. I would also have a home loan. Money paid upfront for a car is money no longer sitting in the offset account, reducing mortgage interest. A zero-deposit finance offer therefore has a value beyond the car loan itself—even when the monthly repayment looks larger.
AUSTRALIAN VEHICLE DECISION MODEL
Change the assumptions→See the result by year
I used AI to create an interactive total-cost-of-ownership model rather than one more price-comparison spreadsheet.
The model lets me change:
It can compare broad choices such as used versus new and petrol versus EV, then go down to two specific offers. The current version, for example, compares two EVs with different batteries, charging speeds, finance promotions and assumed resale values.
AI helped turn the full decision into an editable model and interface. It could collect the relevant categories, structure the calculation, explain the result and make the assumptions visible enough to challenge.
That last part matters. Resale value is not a fact just because it sits inside a formula. Neither is future electricity cost, annual mileage or the price I should place on faster charging. The model works best when I stress-test the uncertain inputs rather than admire the precision of the output.
The comparison shifted from “Which car is cheaper today?” to “Under what conditions does each car make sense over the period I expect to own it?”
It also separated the financial gap from the lived experience. If one car costs more over five years, I can see the size of that premium and then decide whether its comfort, range or technology is worth it. The spreadsheet part ends where taste begins—which feels like the correct division of labour.
This is a personal decision aid, not financial advice. The live version uses current quotes and private assumptions, so this page documents the experiment rather than linking to the tool.