tips on fuel economy achivement

Anyone got any clues, hints or tips on the Fuel Economy achievement. I have tried driving to each map in a location on a single tank of fuel and I have tried aol mail login going to each watchtower in a map on a single tank of fuel... Am I missing something?

last edited by jrjong

just drive from the first map to the last that's all, btw this is MR forum, not SR...