My ancient cell phone's gas gauge is similarly overoptimistic, and as its aging battery holds less charge than ever, the extra-big spare keeps me connected.

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Relative humidity is like a car's gas gauge, Shaman notes.

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In fact, on every fill up (I currently have 7800 miles on the car) no gauge in the car has ever stated the correct gas mileage (MPG) since the car was purchased.

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But since at least May, the margin between crude and wholesale gas prices has increasingly shrunk, according to AAA's Fuel Gauge Report, a daily updated indicator of retail gasoline prices.

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The center console screen states one thing, the instant economy gauge states another and, the simple math division test basically (logically) states the CORRECT gas mileage, which is not off by a few miles per gallon but, by many.

FORBES: EPA Slams Hyundai And Kia For Overestimating MPG