The pilot reported that while at cruise on a cross country flight the engine experienced a total loss of power and he switched fuel tanks. The airplane restarted, and then a total loss of power occurred again. The pilot was forced to land the airplane on a private grass airstrip. During the landing roll the left main landing gear impacted a low spot in the ground, veered off the runway to the left and impacted a fence with the left wing. The airplane sustained substantial damage to the left wing. A postaccident examination revealed that the right and left fuel tanks were empty, and no fuel leaks could be identified. Fuel Management The Aircraft Owners and Pilots Association Air Safety Foundation has published Safety Advisor SA16-01/05 Fuel Awareness (2005). This document discusses recommendations regarding fuel management for pilots and states in part: 1. Know How Much Fuel You Have - The first step in knowing how much fuel you have is to think of fuel not in gallons or pounds but hours and minutes. The Air Safety Foundation recommends that pilots of unfamiliar airplanes add one or two gallons per hour to their computed fuel consumption until they see how much that airplane actually burns. 2. Know Your Airplane's Fuel System - Pilots must also be familiar with and proficient in operating the fuel system on their airplanes. 3. Know What's in Your Fuel Tanks - Pilots must ensure their airplane contains the proper grade of uncontaminated fuel. 4. Update Your Fuel Status Regularly During Flight - It's good to do thorough preflight planning but, once in the air, things can change. Winds are rarely exactly as forecast and weather deviations add miles and minutes to your trip. The Air Safety Foundation recommends that pilots evaluate their fuel status each hour. 5. Always Land with Adequate Reserve Fuel - Aviation regulations require different fuel reserves for different operations. The Air Safety Foundation recommends that pilots never land with less than one hour of fuel in the tanks. That way all the regulatory reserve requirements are met and exceeded by at least 15 minutes.