Decision rule
If you drive under 5,000 km for business and don't want the receipts paperwork → cents-per-km.
If you drive over 5,000 km business OR have a higher-cost car (fuel + services + insurance + depreciation) → logbook usually wins by a wide margin.
ATO on car claims
The ATO cross-references car logbook claims against toll-road data (Linkt, EastLink), fuel-card purchases, and rideshare platform trip data. Inflated business-use percentages are a known audit trigger. See the ATO programs guide.
Cross-references
Run the side-by-side in the Motor Vehicle Deduction Calculator.