The sticker price only tells you what you pay on day one. From there, every kilometre adds fuel or charging costs, the car steadily loses resale value, and bills for insurance, tax and maintenance keep coming. CompareCarCosts.com adds all of that up for both cars and shows you the difference — over the exact period you plan to own them.

The 5 steps

The comparison runs through a short wizard. Each step asks one simple thing:

1. Country. Taxes, energy prices and resale values are different in every market, so we start here. We currently support Germany, Spain, Switzerland, France and Italy (Germany and Spain also for an 8-year horizon).
2. How you drive.Tell us how long you'll keep the car and roughly how far you drive each year. We use this to spread costs over your ownership period.
3. Pick the electric car.Choose the Tesla model you're considering — that's where our data is most complete today.
4. Pick the petrol or diesel car.The car you'd buy instead. Choose the make, the model, and the fuel.
5. See the result. We show the total cost of each car side by side, the difference between them, and what that works out to per year, per month and per kilometre.

What we actually calculate

For each car we model the costs that genuinely move the needle, then add them together over your ownership period:

• Depreciation— the resale value the car loses while you own it. This is usually the single biggest cost of owning a car, and it's the part most people overlook. We estimate it from real residual-value data for your country, car and ownership length.
• Energy— electricity to charge the Tesla versus fuel for the petrol or diesel car, based on each car's real-world consumption, local prices, and how far you drive.
• Maintenance & tyres — scheduled servicing and repairs for the combustion car, plus a set of replacement tyres every 40,000 km for both.
• Insurance — typical annual premiums for the car type in your country.
• Road tax — the annual circulation or ownership tax that applies where you live.
• Financing interest— optional. If you tell us you're taking a loan, we add the interest you'd pay on top.

Where the data comes from

We want to be straight with you about what these numbers are. Every figure is a modeled estimate produced by a total-cost-of-ownership model built on published prices, energy and fuel costs, insurance and tax tables, and historical resale data. They describe a typical owner — your own bills will vary with your driving style, insurer, tariff and the deal you negotiate.

A few honest limits today: the electric side currently covers Tesla, where we have the most reliable data, and the petrol/diesel side covers the makes we have full cost data for — with more brands and countries planned. These estimates are meant to inform your decision, not replace it, and are not financial advice.