Continue from the powertrain cost comparison
Build the shortlisted vehicle in detail, test whether the powertrain fits real journeys and understand how unlike energy units should be compared.
Which assumption drives the result?
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Compare two powertrains without hiding the assumptions
A lower purchase price does not guarantee lower ownership cost, and cheap energy does not automatically recover a large difference in depreciation or finance cost. This calculator puts both effects in the same time and distance boundary.
Either side can represent petrol, diesel, HEV, PHEV, BEV or hydrogen FCEV. The names are editable, so the comparison can also cover two trims with the same technology. It does not load model averages; every figure remains visible and replaceable.
This page is built for side-by-side comparison. Use the single-vehicle Car Cost Calculator when each insurance, tax, service, tyre and parking item needs its own audit trail.
Total ownership cost formula for each vehicle
The cheaper result is the lower of the two totals. Average yearly savings divide the absolute difference by the ownership years. Cost per kilometre divides each total by all kilometres driven.
Loan principal is not added again because it pays the already entered purchase price. Only interest and lender fees belong with one-time and finance costs. Incentives should reduce the purchase price only when they genuinely reduce your own acquisition cost.
Energy formulas for six vehicle types
| Powertrain | Energy calculation | Important input |
|---|---|---|
| Petrol or diesel | Distance × L/100 km × price/L | Long-term real fuel economy and correct gallon conversion |
| HEV | Same liquid-fuel formula | Measured consumption including the hybrid system’s effect |
| PHEV | Fuel for engine distance + grid electricity for electric distance | Real electric-distance share, not only a test-cycle weighted value |
| BEV | Battery demand ÷ charging efficiency × price/kWh | Blended home, work and public charging price |
| Hydrogen FCEV | Distance × kg/100 km × price/kg | Achievable consumption and locally available hydrogen price |
Make both vehicle scenarios comparable
Use the same ownership years and annual distance, but choose vehicle-specific purchase prices, resale values and annual costs. Compare cars that can perform the same task: passenger space, payload, range, towing and equipment should be close enough for the financial result to matter.
Keep tax boundaries consistent. Do not enter a tax-inclusive purchase price on one side and a recoverable business price on the other. Apply grants, rebates, charger support and trade-in bonuses using the same personal-cost perspective.
A low-cost home charging assumption is not comparable with petrol bought at motorway prices unless that charging mix and refuelling pattern are actually expected.
Depreciation can outweigh energy savings
Purchase price minus resale value is the amount of vehicle value consumed by the scenario. A higher-priced car can still compare well if it retains more value; a cheap energy source can lose its advantage if the resale assumption is too low.
Obtain comparable future values for the expected age and mileage. Because resale markets change, save at least conservative and favourable cases for both vehicles. Avoid assigning a universal depreciation rate to every electric, hybrid, combustion or hydrogen model.
Use the Car Depreciation Calculator when the future-value assumption needs its own schedule and sensitivity test.
Cost breakdown over the selected ownership period
The difference column shows Vehicle A minus Vehicle B. A positive number means A costs more in that row; a negative number means B costs more.
| Cost category | Vehicle A | Vehicle B | A − B |
|---|---|---|---|
| — | |||
What break-even annual mileage means
The calculator separates fixed ownership cost from propulsion cost per kilometre. It then solves the distance at which both multi-year totals are equal:
A positive crossover means the ranking changes at that annual distance. No positive crossover normally means one vehicle is cheaper in both fixed and variable terms, or the mathematical intersection lies below zero.
The calculation holds resale values and annual non-energy costs constant as distance changes. In reality, high mileage can alter depreciation, service and tyre costs, so treat the result as a screening threshold.
Distance sensitivity: low, entered and high use
The table compares half the entered annual distance, the entered value and 150%. It recalculates energy and total cost while leaving the other assumptions unchanged.
| Scenario | Annual distance | Vehicle A total | Vehicle B total | Lower cost and difference |
|---|---|---|---|---|
| — | ||||
PHEV electric share and charging mix need special care
A plug-in hybrid can produce very different costs depending on how often it is charged and how much distance fits inside electric operation. Enter engine-mode fuel consumption for the non-electric share—not a test-cycle value already blended with electricity.
For PHEV and BEV, the electricity price should represent energy taken from the grid. If the entered kWh/100 km was measured at the charger, it may already include losses; in that case set additional charging loss to zero. Public rapid charging can materially change the weighted price.
Worked example: petrol car versus battery electric car
Over five years and 15,000 km/year, Vehicle A has fixed ownership cost of €33,500 and energy cost of €0.1224/km. Vehicle B has fixed ownership cost of €38,000 and energy cost of about €0.07043/km.
- Vehicle A energy = 75,000 × €0.1224 = €9,180; total = €42,680.
- Vehicle B energy = 75,000 × €0.07043 ≈ €5,282.61; total ≈ €43,282.61.
- At 15,000 km/year, Vehicle A is cheaper by about €602.61.
- Crossover = (€38,000 − €33,500) ÷ [5 × (€0.1224 − €0.07043)] ≈ 17,320 km/year.
- Above that simplified threshold, B’s lower energy cost can recover its €4,500 fixed-cost disadvantage.
Exercise for automotive-business and vehicle-technology students
Compare a HEV with fixed five-year ownership cost of €31,000 and energy cost of €0.095/km against a PHEV with fixed cost of €34,500 and blended energy cost of €0.055/km. Find the annual break-even distance over five years and identify the cheaper vehicle at 12,000 km/year.
- Fixed-cost difference = €34,500 − €31,000 = €3,500.
- Energy advantage of PHEV = €0.095 − €0.055 = €0.040/km.
- Break-even = €3,500 ÷ (5 × €0.040/km) = 17,500 km/year.
- At 12,000 km/year, lifetime distance is 60,000 km.
- HEV total = €31,000 + 60,000 × €0.095 = €36,700.
- PHEV total = €34,500 + 60,000 × €0.055 = €37,800, so HEV is cheaper by €1,100 in this scenario.
Common comparison errors
- Comparing cars of different size, capability or equipment without noting the trade-off.
- Adding loan principal after already entering purchase price.
- Using a PHEV weighted test figure as engine-only fuel consumption.
- Applying charging losses to consumption already measured at the grid.
- Using only cheap home charging while most energy will be bought publicly.
- Leaving insurance, tax, maintenance or tyres out on one side.
- Using the same resale percentage without model-specific evidence.
- Treating break-even mileage as exact while keeping mileage-sensitive resale and maintenance fixed.
- Calling the cheaper entered scenario the universally better powertrain.
Limits and next Automotive calculator
The model keeps energy prices, annual non-energy costs and consumption constant. It does not price time spent charging or refuelling, tax-rule changes, battery or fuel-cell replacement risk, unplanned repairs, inflation, present value, investment opportunity cost, business taxation or environmental externalities.
Run current, high-energy-price and conservative-resale cases. A durable choice should not depend on one optimistic input.
Next comes the EV Range Calculator, focused on usable battery energy, consumption, reserve, weather and auxiliary loads rather than repeating this ownership-cost comparison.