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  1. #1

    mpg for 300 4.9inline 6

    Anyone know what it can get

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    Also. Will this inline six bolt up to the 351m tranny I don't know what one it is its a 77 f150 and can I get a tranny that will have a granny low manual that will fit on either?
    ;-)

  2. #2
    Da Professuh Raptor05121's Avatar
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    4.2L V6 - M5OD | SCT XCal 3 @ JawsRacing | K&N Series-77 | 16" Dual Efans | Magnaflow High-Flows
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  3. #3
    Junior Member sbow's Avatar
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    I had a 91 f150 lariat with a 4.9 inline that was fuel injected and I could get 20 mpg if I stayed on roads were speed limit was 55 or less. On interstate were speed limit was 65 to 70 it dropped to around 15 mpg. I know that sounds wrong but that's what it got all the way up to 320,000. Also has a 84 f150 with 4.9 inline that wasn't fuel injected that only got about 14 at its best. Still like the 4.9 motors though.

  4. #4
    I'm from Detroit and know a few engineers. Apparently because of federal CAFE standards, the 4.9L is designed to achieve its maximum fuel efficiency at 55-58 mph. This is because of the 55mph national speed limit that was in effect at the time. My 1987 F150 usually gets 16mpg at 55-60mph. If I rum 65-70mph, the mpg drops dramatically.

  5. #5
    Chief Moderator Jersey_Joe's Avatar
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    Quote Originally Posted by CaptBill1957 View Post
    I'm from Detroit and know a few engineers. Apparently because of federal CAFE standards, the 4.9L is designed to achieve its maximum fuel efficiency at 55-58 mph. This is because of the 55mph national speed limit that was in effect at the time. My 1987 F150 usually gets 16mpg at 55-60mph. If I rum 65-70mph, the mpg drops dramatically.
    Welcome Captain.

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