2019 5.0 FX4
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The knock sensor in most modern engines will automatically adjust timing to the fuel you use. So with higher octane gas, they will run with more timing advance, which can provide slightly more power and efficiency.
It used to be when gas was around $4/gal, but the price difference between 87 an d91 octane was only 20c, it was cost effective to go with higher octane gas. But now that gas stations are charging a bigger difference between the grades, it's not so clear. You can do your own mileage tests to see if you get any significantly different mileage with the different grades, and decide if it's worth the cost difference. But if you really can't find 91 octane, then your choices are limited.
It used to be when gas was around $4/gal, but the price difference between 87 an d91 octane was only 20c, it was cost effective to go with higher octane gas. But now that gas stations are charging a bigger difference between the grades, it's not so clear. You can do your own mileage tests to see if you get any significantly different mileage with the different grades, and decide if it's worth the cost difference. But if you really can't find 91 octane, then your choices are limited.
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monkey nutz
Ford Inline Six, 200, 250, 4.9L / 300
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Mar 13, 2006 09:51 AM
