Measuring oil consumption
Start and end with the same oil level under the checking conditions specified in your vehicle manual. Record distance and every top-up. Added oil represents consumption only when the original level is restored; temperature and vehicle angle can distort the comparison.
L/1000 km = added liters ÷ distance(km) × 1000
Worked example
If 0.5 L restores the level after 5,000 km, measured consumption is 0.1 L per 1,000 km. Under unchanged conditions, another 10,000 km would require about 1 L. A zero top-up at the same level means zero measured consumption for that period; distance per liter is then undefined.
Why the result is not a diagnosis
The result summarizes measurements without separating leaks, combustion losses and measurement errors. There is no universal limit for every engine: compare with manufacturer specifications and the history of your vehicle. The projection assumes constant consumption, which can change with load, oil viscosity or mechanical condition.