in so doing, a little of the higher (or inversely lower) octane gas (in the hoses) should end up in your tank and might give you a bit of a boost (if higher octane)...
(remember reading this comment that your mileage may vary ;)
another trick is to watch who buys gas - try to fill up right after someone who choose a higher octane than you and avoid someone who picks a lower octane
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higher octane fuel DOES NOT have a higher number of BTU’s per gallon ... if your car doesn’t ping on regular then use regular ... many high dollar imports “require” unleaded premium ,, in many instances ,, my Mercedes for instance ,, it is not true ,, the car runs fine without pinging on mid-grade,, only buy what you need and only fill up when empty ,, filling up at half tank wastes your time as you’re filling up twice as often.