Here’s a quick bad joke for you courtesy one of my automotive colleagues here at About.com: A [insert the politically incorrect interpretation of a general idiot of your choice”> pushes a BMW into a gas station and tells the mechanic it died. After he works on it for a few minutes, it is idling smoothly. “What’s the story?” asks the car owner. “Just crap in the carburetor,” replies the mechanic. The owner asks, “How often do I have to do that?”Ok, the joke is really bad, but it does remind us of one minor auto repair maintenance procedure that can save you big money. The best way to keep crap out of your fuel system (regular dirt and dust, too) is to keep your air filter clean. If you haven’t replaced your air filter recently, now’s the time to get to it. News source: About autos .com,