Oh come on! It's the same thing. Don't go on making stuff up. Motor oil, Engine oil, it's the same thing. If you say Motor Oil, which motor? Diesel Motor or Gasoline? Every country has it's own norms. Try asking for "Gas" in uk. Very common in USA and Canada to call "Petrol" as Gas, not so much in UK.
In order to survive in Pakistan, you need to know the local lingo of mechanics, i.e Hissa, Gaadri, Chimta etc. BTW, here's the reference for Motor Oil for you: https://en.wikipedia.org/wiki/Motor_oil
As for Vaseline, if you walk into a shop and ask for Vaseline, any half educated guy will suggest alternatives. It's just like pharmacies, you ask for Paracetamol, and you get options based on what is available.
