he recommended fuel type for a Ford Flex
Regular Unleaded - like anything else.
From pg 349 of the Flex 2009 manual: Fuel quality If you are experiencing starting, rough idle or hesitation driveability problems, try a different brand of unleaded gasoline. “Premium” unleaded gasoline is not recommended for vehicles designed to use “Regular” unleaded gasoline because it may cause these problems to become more pronounced. If the problems persist, see your authorized dealer.
i have a 278000 mile ford flex sel 2013 i have ran 85 octane for many years and also now only run 91 octane getting average of 25mph..hope this helps.
Octane rating is a measurementof a fuels resistance to detonation. It won't improve your fuel economy. IN fact, it may make it worse. Sorry but if you want fuel economy you should buy a small car.
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