As a result, varying rates of oil consumption are accepted as normal in all engines.Checked 2026-08-12
Engine oil consumption
Oil an engine uses internally between changes, as distinct from oil lost through a leak.
Also called: oil burning · oil usage
What it means
Definition
Oil consumption is oil that leaves the engine without leaking out of it. A film of oil coats the cylinder walls to lubricate the pistons and some of that film burns during combustion, so every engine uses some. GM's own guidance states that varying rates of oil consumption are accepted as normal in all engines. BMW adds a design factor: engines fitted with a turbocharger, as part of their normal operation, will consume engine oil at a higher rate than a naturally aspirated engine.
Why a buyer cares
What it changes
A car that needs oil topped up between changes is not automatically leaking or damaged. The useful question is whether anyone has checked for a leak, and what the manufacturer's own guidance for that engine says.
In practice
Where you meet it
On the dipstick, in an inspection note about oil level, and in what a seller says about topping up.
Two things that look alike
Not the same as
A leak escapes past a seal or gasket and leaves evidence on the engine or the ground; consumption leaves none.
Read next
Related terms
Turbocharger
An exhaust-driven compressor that forces extra air into the engine.
Positive crankcase ventilation (PCV)
The system that routes gas leaking past the piston rings back into the intake instead of venting it.
Head gasket
The seal between the engine block and cylinder head that keeps combustion, coolant and oil apart.
Where this comes from
Sources
Engines that are fitted with a turbocharger, as part of their normal operation, will consume engine oil at a higher rate than a naturally aspirated engine (non-turbocharged engine).Checked 2026-08-12
Both manufacturers publish consumption thresholds in these documents. None is quoted here, because a threshold from one maker's bulletin does not transfer to other engines.