AMC Eagle Den Forum

The Mighty 258 => Fuel Systems. => Topic started by: ScreamingEagle82 on February 03, 2012, 08:44:01 PM

Title: Fuel Efficiency
Post by: ScreamingEagle82 on February 03, 2012, 08:44:01 PM
This may be a dumb question, but on average, what kind of fuel efficiency can I expect on an Eagle Sedan? I mean, i know all cars are different, but just a ball park figure would be helpful. Thanks.
Title: Re: Fuel Efficiency
Post by: DaemonForce on February 03, 2012, 10:01:13 PM
My 83 Eagle wagon has a stock 258 motor with several blown gaskets, the stepper motor two pot carb with a mess of intake issues. Transmission is a Torqueflite automatic. Since I mainly use my car for really quick freeway trips it gets anywhere between 16-20MPG. If I were to swap in a rebuilt 258 I'd likely see between 22-24MPG. With an overdrive transmission it would easily be 30-32.
Title: Re: Fuel Efficiency
Post by: doc65 on February 03, 2012, 10:17:34 PM
Daemon,

That would be great, my 85 will ultimately get a complete 93 Cherokee 4.0 drivetrain, FI,  / AX15 Manual with overdrive & 3.07 gears(because the same cherokee has a D35 with that ratio & I figure I can find or make a front to match).  I'd love to see it get 30 or so...

Doc

Title: Re: Fuel Efficiency
Post by: DaemonForce on February 03, 2012, 10:24:31 PM
Aha...I snagged a 4.0 head off a 92 Cherokee a few days ago and I'm still trying to decide what to do with it. I can put it on my spare 258 block but I have no idea what I'll do from there. I want to rebuild a simple Carter carb to eliminate the electronic garbage but I could also go fuel injection. Not sure if I should pick an AMC or Chrysler manifold though. They look different and that tells me they might perform different too.
Title: Re: Fuel Efficiency
Post by: doneagle on February 04, 2012, 12:42:24 AM

      HI  My 1983 wagon is stock and around here she gets 24.2 and highway she gets 26.8......My 1982 wagon got
           24.0 mpg highway ....they are stock cater crab and all vac..........Don
Title: Re: Fuel Efficiency
Post by: BenM on February 05, 2012, 09:10:32 PM
There's several long threads in the archives where people have posted their fuel economy.

Generally around 18 with an automatic in the wagons, maybe slightly better in the 2-door and 4-door full sized cars. The Kammback and SX/4 get better figures. If you have 2.35 or 2.73 gears, you essentially have a similar ratio to overdrive it top gear.

I think Gill averaged around 25 in his auto SX/4 with mostly highway driving.