Fluid Necessity - Dead Island Sidequests Walkthrough

You get the fluid necessity side quest from Harlan after helping him in the Make Yourself at Home quest.

You will learn from Harlan that he is an airport pilot who got stuck trying to reach the island airport. You helped him get a shelter already in the make yourself at home sidequest, and now he wants you to get him some gas to power the generator and restore electricity.

Your mission is to deliver to Harlan 2 cans of gas from a gas station.

Get into your truck and pass through the 2nd tunnel to reach the far gas station. Locate two gas cans there. There is one in one of the warehouses and another two canisters of gas in a second warehouse. You can fill them up with gas (although it doesnt seem necessary for this quest)

Load the canisters in your truck and deliver them back to Harlan, place them in the designated spot (marked by the grey shadows) to complete this quest and get your reward.