My Expedition Limited has a 28 gallon tank (about 105 Liters) Ford recommends using 87 Regular unleaded gasoline (petrol) as the Triton engine is designed to run off of the cheapest low quality fuel available without hindering performance. But I still fill it up with 89 Mid-Grade, so it takes me close to $100 dollars to fill it up (depending on which gas station I fill it up at) I get around 16 mpg driving around Wilmington, and I can squeeze 19 to 20 mpg on the highway ... but I don’t drive with the accelerator pushed to the floor either. Whenever I go Off-Road or I’m using it to tow/haul something, you might as well forget gas mileage, because it’s just not there anymore.