From cnn.com:
By Julianne Pepitone, CNNMoney.com staff reporter

If you're filling up your tank with super gasoline, chances are your wallet will soon be running on empty. The special stuff costs up to 20-40 cents more per gallon than regular gasoline, even though it doesn't do anything to improve the performance of most cars...

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Does this sound like you? Any mechanics or auto experts out there who disagree?