Mexico’s state oil company  says it will no longer use pipelines to ship finished, usable gasoline or diesel amid a wave of fuel theft.

Petroleos Mexicanos, or Pemex, believes that last year it lost more than a billion dollars’ worth of fuel to thieves who drilled thousands of illegal taps into pipelines.

Pemex said Tuesday it will only ship semi-refined fuels “that are not yet usable in vehicles and industrial plants” through its pipelines. The final refinement stage will be performed at distribution terminals and tank farms, before the fuels are distributed to gas stations and industrial facilities.

Pemex warned drivers Tuesday not to buy fuels from unauthorized sources “given that because they are not fully processed, they could damage motors.”

Source: PennEnergy