That is your decision and no problem if you do, but the game is very playable without the oil option. We shoudl just have cut out all the additional features like this for PSP and DS but we foolishly wanted to give as many options as possible. I always have it off and just raise the difficulty leve...

Great game, and really nice to have this sort of game on the PSP.

However after not much play decided limited oil was the only way to play, and then got these crashes (playing Axis).

Checking here I see there isn't a solution, so I will be returning the game to the retailer.