As gas prices inevitably rise, motorists are becoming wary of dodgy gas stations that are skimping on the amount fuel that they’re actually being charging for. Although a majority of service stations are mostly honest, and it’s very rare to find one that’s actually cheating customers, gas inspectors in the state of Michigan are making their presence felt. Last year, only five stations out of a state-wide total of 5100 were charged with shorting customers. The most notorious was a Fast Track near Detroit that ripped of customers to the tune of $100,000 per year.

Run by the state’s Department of Agriculture, 14 inspectors randomly measure “gallonage” accuracy. The process involves pumping gas into a measuring tank until the meter reads 5.000 gallons exactly. The pumps are allowed a 3.3 ounce buffer, which equates to a 0.5% margin of error. If a pump is outside the accuracy window, it is “condemned for repair.” To test the quality of fuels, samples are sent to a lab, and out of 2816 samples that were processed for 2005, 217 failed, mostly due to a low octane rating.

[Source: Car and Driver]