TCO v6: what changed in the car cost calculator

RealTCO 6.0 compares cash, a loan, a lease with buyout and a rental with return for the same car. You can enter your own costs, exclude individual categories and inspect the assumptions behind the result. We also corrected tax, resale-value and financing calculations. Some business results therefore differ from version 5.

This guide describes the release of 5 September 2026. Tax discussion concerns Poland. It explains calculator changes, without ranking brands or presenting current commercial offers.

One engine for private and business use

The private profile compares gross costs without business tax deductions. The business profile lets you choose mixed or business use, VAT registration and income-tax treatment. VAT registration is a separate setting: choosing a business profile does not itself establish a right to deduct VAT. Under Polish revenue-based ryczałt, expenses do not produce the usual income-tax cost shield.

The Toyota and BYD sales views use the same formulas. The brand determines the starting catalogue and some vehicle assumptions, without a special multiplier that improves its result. A broker's insurance quote or a service budget can replace an estimate.

Your own costs, including an explicit zero

Each cost category can use the automatic model, a manual amount or exclusion. Categories include fuel and electricity, maintenance, repairs, liability and comprehensive insurance, tyres, assistance, parking, road charges, inspections and other running expenses. A manual budget replaces the estimate before tax and totals are calculated.

The financing comparison retains common operating budgets. If insurance or maintenance is included in the rental payment, marking that service as included removes the extra expense only from the rental option. Your declared budget still applies to the other options.

Four financing options with an explicit contract ending

Cash means purchasing the car. A loan separates the down payment, principal and interest. An operating lease includes the initial payment, instalments and buyout. Terminal vehicle value affects ownership cost in these options.

A pure rental ends with return. It counts rent, the initial fee, uncovered expenses and the declared return settlement. It adds neither a vehicle purchase nor interest outside the quoted rent, and deducts no resale proceeds. Equipment included in the rental belongs to the rented vehicle; its reference value can affect the tax-limit basis without creating a separate purchase charge.

Rental requires a monthly payment and a term matching the analysis horizon. Total included kilometres and the excess-kilometre rate allow an over-mileage charge to be calculated. Missing mileage terms mean missing information, with no excess charge calculated; they do not mean unlimited mileage. A loan, lease or rental without a quote remains unavailable. The comparison is marked incomplete when offers are missing.

For worked numbers, see rental, lease, cash or loan in Poland. Those inputs are educational assumptions. If a cash discount is unavailable with a lease, use separate scenarios with the applicable prices.

What changed in tax, resale value and NPV

• VAT and deductible expenses: recovered VAT is no longer counted again as an income-tax expense. Maintenance and other included running costs go through the shared tax calculation.
• Vehicle sale: gross resale value, output VAT and the income-tax basis are separated. A manually entered residual value is your assumption, not evidence of a guaranteed buyback.
• Plug-in hybrids: the Polish value limit depends on CO₂ data. The powertrain label or missing emissions data alone does not establish preferential treatment. The Polish Ministry of Finance explains passenger-car limits.
• Bundled services: covered expenses are removed before tax. For business rental, a quoted service portion is treated separately. Without that split, the calculator discloses a conservative deduction assumption. The basis includes the Ministry's explanation of business vehicle expenses, with subsequent value-limit changes.
• Financing: purchase price and instalment principal are not added twice. The old single-payment field without full contract terms is rejected because it cannot separate principal repayment from financing cost.
• Net present value: discounted cost follows payment timing. Rental deductions for rising service costs and changing insurance premiums are assigned to the expense year. The opportunity cost of capital is shown separately.

Why an old result may change

We compared the versions using 36 synthetic scenarios: four powertrains, three usage profiles and three financing methods. Within that set, private cash and loan results were unchanged. Leases and business calculations showed differences from the financing and tax corrections. This does not promise an identical result for every private scenario.

Older presentations retain their historical figures. Before preparing a new offer, recalculate the saved assumptions in v6. Check the discounted purchase price, term, mileage, tax profile and source of resale value. A newer engine does not validate an old dealer price.

Inspect and export the result

The result includes cost categories, assumptions, yearly amounts and tax details. Average monthly TCO covers the whole analysis period; it is not the contractual instalment. Editing the form invalidates the previous verdict. Calculation failures do not become zero-cost cars or invented savings. The export records the inputs together with the engine response.

Limits that still matter

Automatic resale value, repair and insurance amounts remain forecasts. Tax deductions assume an ordinary VAT invoice; margin-scheme invoices, historic depreciation and special transactions require separate analysis. The sale VAT correction uses annual periods. The comprehensive-insurance tax limit uses purchase value rather than a separately declared insured value for each year.

Rental does not model refundable deposits, unknown return damage or early termination costs. The initial fee means a non-refundable expense. Loan and lease inputs use nominal interest without automatically adding commissions; that rate is not APR/RRSO. A usable comparison needs the terms of your actual offers. These tax explanations do not describe UK or German tax law.

The TCO v6 methodology explains the formulas, data provenance and limitations of tax and NPV calculations.

Open TCO v6 and enter your costs. Choose a private or business profile, then compare contracts for the same vehicle, mileage and period.