Thinking with their wallets, and avoiding $4.59/gallon fuel prices, truck owners in the States have been sneaking across the Mexican border to fill up with low-cost diesel (in Mexico, the fuel averages just $2.20/gallon). While filling a primary fuel tank isn't illegal, Mexico prohibits additional fuel tanks (aka auxiliary tanks) to be filled and moved across the border, so many truck owners with long-range tanks are finding themselves breaking Mexican federal law. Truck owners are getting stopped on the Mexican side of the border and their trucks are confiscated while authorities run tests to determine the origin of the fuel. If found in violation, owners face stiff fines. The Mexican Consulate is offering a blanket warning for all truck owners equipped with secondary fuel tanks to not drive those vehicles into Mexico. Not only do those owners risk truck confiscation, but the Mexican fuel is not formulated to U.S. ultra-low-sulfur regulations meaning emissions components will likely be damaged. (As if the trucks breaking the law are fitted with emission components in the first place...)

[Source: PickupTrucks.com]