Similar to how Bob Uecker described the best way to catch a knuckleball by, "Simply wait for the baseball to stop rolling and just pick it up", I simply just wait for the needle to stop jiggling and know that I have 30 miles to find a gas station. For every mile after the 30 Mark equates to how many miles I need walk to a gas station. Perfect plan? No, but I do generally get to meet a lot of nice people who want to give me a lift when they stop to look at my old truck. I never seem to have to wait very long for someone to stop.