Even if it means using two gallons of gas while waiting in lines at the border, a new trend of filling up your tank in Mexico is worth it for those who have SUVs and trucks. Regular gas costs $2.54 a gallon at Pemex stations in Tijuana compared to San Diego, where it's over one-dollar higher at $4.624. Then you've got diesel at $2.20 in Tijuana vs. $5.04 in San Diego.

However, one problem does exist with the fuel: "Mexican gasoline has higher concentrations of sulfur than U.S. fuel. That doesn't mean that American cars won't run well on Mexican fuel, but it could affect the life span of catalytic converters used in motor vehicle exhaust systems to reduce harmful emissions," reported the San Diego Union-Tribune. “'It's possible that after many years of using Mexican gasoline, a car could fail the California smog test,' [fuel research Alejandro Díaz Bautista] said."

Photo by drini via Flickr