It's not like petrol at all and you can't compare their value in terms of price movements
Petrol is a single use consumable commodity whose value is derived from its utility and its ability to do stuff
Gold bullion's value is derived from completely different properties
Their prices are both subject to supply and demand and their respective markets provide a mechanism for price discovery (ignoring market manipulation).
Sometimes the prices go up, sometimes they go down but their intrinsic value remains unchanged. Fear and greed are the main driving forces of all markets