Have you ever pulled up to the
pump, and found to your amazement that your
gas tank, which normally holds only twelve
gallons, can suddenly fit fourteen? Chances are that you haven't come across a magical tank-expanding gasoline, but instead that you are the victim of a
skimming scam. Most gas station owners are reputable businesspeople who won't entertain such tactics, but every tree bears a few bad apples, and in the gasoline sales business, these types will skim profits out of your tank. The process is fairly simple; they adjust the flow reader of their pumps so it appears that more gas is coming out than actually is. For every gallon the machine thinks it is giving you, it may only in fact be delivering nine tenths of a gallon. Naturally, for fear of getting caught, only the most brazen of tricksters would set their flow readings to diverge so obviously from the quantity of fuel actually being pumped. More likely, the unscrupulous are cheating by hundredths, and not tenths, though the trickle adds up both for them and negatively for their customers.
If you feel you've been scammed in this way, it is likely of little use to confront the
station attendant -- most gas stations are staffed on a day-to-day basis by
wage workers who would be unaware of what sort of settings are in place on the pumps (and, probably, would lack the technical
acumen to even determine if anything were awry). Plus, a set-upon station owner might well point out that filling up of a gas tank is a vague exercise -- certainly sufficiently so that this kind of skimming is easy enough to get away with. The
needle running the range from full to empty is a highly inexact
barometer of just how much gas you've got left, and how much will fill your tank. And other factors, even the outside
temperature, can subtly effect the capacity of your tank. It might be, as well, that the pump is innocently malfunctioning, though one might expect a malfunction which financially favors the
purveyor might not get much attention insofar as repairs are concerned.
You, as
consumer, can easily test a given pump if you've got the time and inclination by simple bringing along a canister of exact size, such as a one-gallon can, and filling it to that gallon line, and see whether the pump accurately reflects the amount provided. If you are fairly confident you've been scammed, the best you can do probably is to contact your local authorities and buy gas elsewhere.* Gas station pumps are generally
inspected for
accuracy at infrequent intervals, perhaps once a year or once every several months, with surprise inspections being a rarity. Buying from well-known name brands offers no
panacea, as gas stations are typically
franchises, whose corporate overlords have little concern for what their retailers are doing so long as enough dollars are pouring in to the corporate end. In fact, you might well have better luck with a small independent whose stock in trade is the reputation of their services. This is especially so if the independent is, as well, an auto shop, which offers gasoline primarily as a draw for customers to get to know them and have them in mind when more significant repair work is needed.
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Note: There is a different and unrelated kind of 'skimming' which goes on at gas pumps wherein thieves attach devices to the pump
credit card readers in order to steal credit card information from gasoline buyers. Considering all of the ways in which buying gas can bite you (even above and beyond the price of gas itself), the safest bet is to minimize gasoline usage altogether with
carpools,
bicycling, and availing oneself of
public transportation. When you must buy gas, it is always safer to pay
cash, unless you are in an altogether seedy
neighborhood where the walk from the pump to the station puts your life or property at risk.
*
misterfuffie notes that the 'authorities' to contact are typically the dept. of agriculture, or the bureau of weights and measures, and that there's usually a sticker somewhere on the pump with the responsible commissioner's name and the date of inspection punched thereon.