Americans Fuel Up On Cheaper Gas Over The Border Of Mexico

TIJUANA, MEXICO - JUNE 27: Massive lines of cars wait daily to cross into the US from Mexico at the San Ysidro border crossing, the world's busiest, on June 27, 2008 in Tijuana, Mexico. With the cost of gasoline in California around $4.60 per gallon, many drivers are buying their fuel in Mexico for about $3.20. There is a price to pay for cheaper gas though. Mexican gas is formulated with more sulfur than California gas and that can damage the emission control equipment on US cars, causing them to fail emissions tests and leading to expensive repairs. In addition, unless a driver has other business in Mexico, part of their fuel savings will be burned up idling in a line that can easily last for hours to get back into the US. (Photo by David McNew/Getty Images)