[gerdesj]

What on earth does that mean?

[kccqzy]

It means the oil is being used for its heat content when combusted. Such heat may be used directly or be converted to mechanical work in a heat engine.

[dboreham]

Exactly what it says? 80% of the oil extracted from the ground is burned. The other 20% is used to make things.

[throwawaysleep]

We burn 80% of the oil we take out of the ground. Oil production could drop 80% and we would not have to change anything other than demand for burning it.