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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 1980cdeluxe on November 15, 2006, 10:54:00 PM

Title: MPG question, 250 Inline
Post by: 1980cdeluxe on November 15, 2006, 10:54:00 PM
Well, my scottsdale 78 2wd muncie 3.42 gears in the rear gets pretty bad gas milage for a single barrel'd 250. I was wondering if anyone had any clue the city miles I should be getting with this, I wouldn't dare drive it over 55mph too much, it revs too high. I would say i'm getting somewhere around 14, which is rather annoying. Ignition is tuned up, timing is correct... I just dont get me and vehicles that burn gas. I'm thinking of selling it to buy a small car, any suggestions?!

Title: 250 I6
Post by: Mr Diesel on November 15, 2006, 11:04:00 PM
I had a '79 250 with a 1 barrel, and it got about 14 city, 17 or so highway. It ran great, though. I was going to put a larger carburetor and intake on thinking it would help the mileage and power, but ended up trading it for a bigger truck. 500 CFM or so 4 barrel and a new intake would probably improve mileage a few mpg's, and definitely the power.

- Mr Diesel
'76 C30 Crew 6.2

Title: Re: 250 I6
Post by: Pushrod on November 16, 2006, 05:00:00 PM
A higher or numerically lower gear ratio. Say uh 2.-- ratio would help.

Lean out the carb without burnin up the motor. It may run a bit hotter.

What kinda Muncie you have there?