I asked the mechanic to check the 'oil'. [=to make sure that there was enough oil to make the car engine run smoothly]
The dressing is made with 'oil', vinegar, and a pinch of herbs.
He works mostly 'in oils'. [=he mostly uses oil paints]
(..) It looks pretty ordinary to me. Keep looking. Your coffee, sir. Decaf latte with non-fat milk. Oh, champion. Steaming sump oil. Wait, what did you do? I don't know. What did I do? - Where is that? - Don't know. (..)2001 Lara Croft: Tomb Raider