What drives TCO?

Why this matters when you buy

Dealers and ads highlight payments or efficiency figures in isolation. TCO forces the same time horizon and the same line items for every vehicle so you can see whether a higher purchase price might still pay off through lower energy cost, or whether cheap fuel cannot overcome depreciation.

How CarCostIQ models it

CarCostIQ sums purchase (MSRP plus optional on-road extras you enter), energy over the period, insurance and maintenance (flat annual defaults you can override), optional loan interest if you use finance fields, then subtracts an estimated residual value at the end. Regional electricity and petrol defaults apply unless you type your own c/kWh or c/L.

Real-world caveats

Stamp duty, rego, and lender fees vary by state and lender; I surface transparent defaults but you should confirm official charges. Real insurance depends on your risk profile. Maintenance spikes when major services fall inside the window. Residual is a simplified fraction of MSRP, not a live market bid.

Simple practical example

Take two reference vehicles roughly $17,000 apart on MSRP. The efficient EV might use ~16 kWh/100 km while the petrol car uses ~6 L/100 km. At 15,000 km/year, with illustrative 30 c/kWh and 190 c/L, the annual energy gap is on the order of hundreds of dollars — over five years that can rival a service pack or insurance swing, but it still may not erase the whole purchase gap. Run your exact models in the tool: swap in your c/kWh (after charging mix), your c/L, and your km to see whether energy is doing the heavy lifting in your scenario.

Common misunderstanding

People often treat a single lower bill (e.g. registration) as proof a car is cheaper overall. TCO needs every recurring cost plus purchase and exit value on the same timeline — skipping residual or insurance skews the answer.

What to override in the calculator

Start with annual km and region, then electricity c/kWh (and charging mix if you use public DC often), petrol c/L, both residual rates, and insurance/maintenance when you have quotes. Add on-road extras only when you are modelling closer to drive-away.

Frequently asked questions

I opened the calculator from a compare page — how do I know the right cars are selected?

A green Preloaded panel lists both model names and the regional default. If you do not see it, pick vehicles from the dropdowns or use the compare page button again. The same query parameters restore fields when you open a shared result link on the home page.

What is included in CarCostIQ TCO?

Purchase price (plus optional on-road extras), energy (electricity or petrol) scaled by annual km and efficiency, insurance and maintenance over the period, optional finance interest, minus an estimated residual (resale) credit at the end of the window.

Why do my real bills differ from the calculator?

Defaults use regional energy averages and flat annual insurance and maintenance so EV and petrol comparisons stay comparable before you add quotes. Replace any field where you already know your numbers.

Does charging mix really change the EV side?

Yes. Home charging at your tariff is blended with a higher effective rate for the share modelled as public DC use. Heavy public charging usually raises average c/kWh and narrows the gap with petrol on energy alone.

Should I trust the residual figure?

Treat it as a planning lever. Used EV markets are still evolving; move the residual sliders to stress-test best- and worst-case exits.

Why is finance optional?

Some buyers pay cash, others finance. Including interest only when you enter loan terms keeps the base comparison focused on vehicle economics.

Where can I see the exact formula?

The methodology page documents line items and calculation order, including how residual is credited against total cost.