An older used car will often be advertised for less than a newer one. The useful buying question is whether the price difference compensates for the differences in equipment, condition, expected maintenance and eventual resale.
AUCN's historical listing extract provides a broad model-year comparison. It cannot establish the depreciation of an individual car, because each model-year group contains different vehicles with different original prices and specifications.
What the asking-price index measures
The reference group is the average asking price of 2025-model vehicles in this extract, set to 100. This is an index, not a percentage of original new-car value. The collection window and listing deduplication were not established, so it should not be described as a current market valuation.
For example, an index of 79.5 for the 2022 group means its average advertised price was 79.5% of the selected reference group's average. It does not mean a 2022 car retained that proportion of its own original value. Model year should also not be treated as an exact vehicle age.
Build a fair comparison set
Start with the same generation, body style, engine, transmission and variant. A generation change can introduce different safety equipment or powertrains, making a simple year-to-year price comparison misleading.
| Dimension | Match or account for | Why it changes the decision |
|---|---|---|
| Generation and variant | Equipment, powertrain, drivetrain and specification | Similar names can describe materially different vehicles |
| Kilometres and use | Documented readings and type of use | Distance alone does not explain wear or maintenance |
| Service history | Required work completed and next work due | Deferred maintenance can offset an apparent saving |
| Condition and repairs | Inspection findings and disclosed history | Cosmetic presentation does not establish mechanical condition |
| Seller and location | Private, dealer or trade-in; comparable region | Preparation, protections and selling costs differ |
| Ownership plan | Expected use, holding period and resale channel | The cheapest purchase may not have the lowest ownership cost |
Remove clearly different variants from the comparison instead of averaging them together. Keep a note of why each remaining listing is a useful alternative.
Compare the full cost of the shortlisted choices
Obtain quotations for insurance and known maintenance, and identify registration and transfer costs for the intended transaction. Ask an inspector which near-term items need attention and distinguish those from possible future repairs.
Then compare the alternatives on the same basis: purchase, immediate required work, ongoing costs and a range of possible resale outcomes. If finance is involved, compare total borrowing cost and terms as well as repayments. The Moneysmart car-loan guide explains the finance comparison.
Do not estimate resale by applying the historical model-year index to today's asking price. That would mix different groups and periods while hiding uncertainty about the specific vehicle.
Worked example: older but better documented
Consider two examples of the same generation and variant. The newer car has fewer advertised kilometres but incomplete service invoices. The older car has a coherent history and recent documented major maintenance.
The index cannot choose between them. Ask for an inspection and cost the missing or upcoming work. A higher purchase price may be justified by equipment or condition, while a lower price may be offset by required work. The decision should be supported by the actual differences, not the model year alone.
Turn the comparison into an offer or asking price
For buying, explain which matched alternatives and inspection findings support the offer. Avoid applying an arbitrary percentage discount for every blemish. Where a material fault is unpriced or unexplained, obtain an estimate or pause.
For selling, choose a price range supported by comparable current listings and your car's documentation. A trade-in offer has different preparation, convenience and resale economics from a private asking price, so compare the overall transaction rather than assuming the gap is pure undervaluation.
Changes to the earlier analysis
The earlier “value retained” curve and brand retention rankings have been replaced. Cross-sectional averages cannot measure an individual car's depreciation, and mixed fuel-type prices cannot establish which powertrain holds value best.
Use the car valuation tool to begin current research and read the methods and publication limits before quoting this historical index. Verify history and condition using the risk assessment guide before turning a price comparison into a purchase.
Frequently asked questions
Does this chart show how much value a car retains?
No. It compares average asking prices of different model-year groups. It does not track the same vehicles from new or measure completed sale prices.
Why is the 2025 model year set to 100?
It is a chosen reference group in the historical extract. It is not a new-car purchase price and is not described as the newest available model year.
Can I use the average to price my own car?
Use it only as broad context. Match generation, variant, kilometres, condition, history and location, then compare current alternatives and your selling channel.