Yes, PETROL is a Scrabble word!

Letter values in Scrabble US: P 3, E 1, T 1, R 1, O 1, L 1.

Is it a valid word?

PETROL is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines