Yes, thats assumed. However we are taking into account that machinery rusts away quickly. If you stop one refinery for example, that's not a smooth change, its an abrupt step. If we stay steady below the usual high, then trying to come back will be expensive. For that reason we'll see the price increase slowly...you need the fuel, so its a seller's market, they need to get paid as if their load was double in case they need to double. At some point it might drop a bit until it becomes a luxury item.

Here's an example where the price is going up became the supply keeps dropping and the demand keeps increasing regardless of the supply situation:

The same would happen to ice cars. People still want to use them if they have them, but the market keeps shrinking.