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    flatie46's Avatar
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    Gas mileage in the CJ's

    What kind of gas mileage do you get in the CJ's? Is there that much difference between the 304 and the 258? I know gear ratio can play a big part in this.

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    Re: Gas mileage in the CJ's

    Yep! gear ratio has a lot to do with it. I get around 8-9mpg , 10 if i'm lucky. However, i also have some mild performance in the engine like the cam, intake and a 750 Edelbrock 4 barrel with the stock axle gears.
    Confucious says: Don't eat the snow where the huskies go!

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    Re: Gas mileage in the CJ's

    I'm thinking along the lines of a daily driver thats pretty much stock. I don't really need the extra HP, just dependability.

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    Re: Gas mileage in the CJ's

    Currently with an engine that I feel is out of tune (timing and carb need to be set) I am getting almost 15 on the highway at 50-55mph. I have a AMC 360 with a stock 4 speed, I am geared at 4.10's front and rear with 33X12.5X15's. Hope this helps.
    P.S. Steel where did you get the manifold for the four barrel? I have a 600 CFM I would like to put on but can't find the manifold???

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    Re: Gas mileage in the CJ's

    Quote Originally Posted by 82CJ7JEEP View Post
    Currently with an engine that I feel is out of tune (timing and carb need to be set) I am getting almost 15 on the highway at 50-55mph. I have a AMC 360 with a stock 4 speed, I am geared at 4.10's front and rear with 33X12.5X15's. Hope this helps.
    P.S. Steel where did you get the manifold for the four barrel? I have a 600 CFM I would like to put on but can't find the manifold???
    Edelbrock. I'm currently using the performer intake and carburator but later on i'm thinking of swapping the intake with the airgap series.
    Confucious says: Don't eat the snow where the huskies go!

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    Re: Gas mileage in the CJ's

    My 78 CJ7, 258, 3 spd std, 4-something gears, 29 inch tires, used to get around 12-15 MPG depending on what kind of driving I did. My 05 TJ (4.0, 6 spd std, 3.07 gears, 31 inch tires) gets 15-20 MPG. I guess all that fancy computer control equipment adds a little bit of mileage. Both Jeeps seem to get worse mileage if pushed on the highway. "Pushed" meaning 55-60 for the CJ and 65-70 for the TJ . I guess we must remember that we're cruising down the road on a concrete block with a tent on top. Ahhh, yes... The aerodynamics of a refrigerator box. -John

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    Re: Gas mileage in the CJ's

    Quote Originally Posted by SteelHeadz View Post
    Edelbrock. I'm currently using the performer intake and carburator but later on i'm thinking of swapping the intake with the airgap series.
    Thanks Steel, I will look into it. Is the "air-gap" intake that much better, or is it just a cooling factor? I know the performance is better the cooler the fuel, but I am not convinced in the cramped engine compartment it will make that much of a difference. If you get it please post as to the performance you get.

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    Re: Gas mileage in the CJ's

    John your right, Jeeps probably aren't much different aerodynamicly from the front or the side. I was hopeing to kinda hear a comparison between the 304 and the 258 as far as fuel mileage. I didn't post the thread that way so it's my fault, but anyway. Personally I like the sound of the V8 but in my opinon the 258 will out last it and take more abuse. I wouldn't care which I owned, both are goood engines. Fuel mileage eats into the family budgit so I'm just tryn' to figure out which would be best for me.

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    Re: Gas mileage in the CJ's

    For the record, I am still running the same engine that GOD and AMC put in my 73. I have a 258 with a 3 speed. I avg about 13 to 16 depending on what I am doing. When I made the trip from Arizona to Missouri, I avg 16 on the open road at 58 MPH. I still run the single barrel and only mod is I put a fancy air cleaner on it. This was with 31in tires. I think I have 4:10 gear but don't quote me.
    So its old, beat up, and hasn't had a bath since 1980. It has character.

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    Re: Gas mileage in the CJ's

    Thanks for the info Weylyn.

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    Re: Gas mileage in the CJ's

    No prob, You could probably be able to do better with injection, Jacobs Ignition. I am looking at A possible engine upgrade for mine, I just have not decided yet
    So its old, beat up, and hasn't had a bath since 1980. It has character.

    The word "martyr" is just a fancy name for "crappy fighter"

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    Re: Gas mileage in the CJ's

    Quote Originally Posted by Weylyn View Post
    No prob, You could probably be able to do better with injection, Jacobs Ignition. I am looking at A possible engine upgrade for mine, I just have not decided yet
    Yea, but that'd be expensive. Might pay off in the long run though. I know you can tinker around and get your mileage numbers up. I've even got a video on how to make a hydrogen generator for less than $50 that may double your mileage [results may vary]. The thing is I've heard different stories over the years. I've heard that you could milk more gas mileage out of a good running well thought out six with electronic ignition. Then I've also heard that the small V8 will do better because it's not having much load on it at all being in a lightweight jeep body and frame. I know the newer jeeps get better mileage and they're pretty cool, but I've always had a thing for the older CJ's.

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    Re: Gas mileage in the CJ's

    I am kicking a thought of Goin a new Jeep frame drive train but a CJ 5 body. Still debating. I have too many other pots on the fire right now so, got to get other projects done first
    So its old, beat up, and hasn't had a bath since 1980. It has character.

    The word "martyr" is just a fancy name for "crappy fighter"

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    Re: Gas mileage in the CJ's

    That sounds like a good project, if you found a roll over it'd work out pretty good. I've been seeing some project jeeps in my area but like you I really don't need something else to work on. [ a man's got to be realistic sometimes] I'd like to buy one that runs and drives pretty good, some rust wont bother me. I'm not interested in pretty paint or chrome. I'll find one when the times right. Gonna try and learn more about 'em till then and keep driving this worn out chreokee.

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    Re: Gas mileage in the CJ's

    1974 with a 304 four barrel. 33" tires 4:56 gears about 8 to 10 miles to the gallon 10 if it is mostly down hill... lol

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    Re: Gas mileage in the CJ's

    Quote Originally Posted by 74trs View Post
    1974 with a 304 four barrel. 33" tires 4:56 gears about 8 to 10 miles to the gallon 10 if it is mostly down hill... lol
    I bet it feels strong with those gears and the 304. It's a good lookin' jeep I might add. I saw a 69 CJ-5 on cragslist the other day that had the V-6. I wonder if they do well on gas.

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    Re: Gas mileage in the CJ's

    Thanks

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    Re: Gas mileage in the CJ's

    I posted this before I bought my CJ-5. After tinkering with it and driving it on some short trips around the block [ about 1.5 miles ] and to the store. I've gotta say the 304 don't seem to be too bad on gas. I've just got a 6gal boat gas tank in it untill I finish all the welding that way I can pull it out easily. I know I haven't driven it enough to give it a good test but I don't think my Cherokee with the 4.0 would have done this good. I haven't owned a V-8 since the early 90's. The last one I had would pass everything but a gas station. I know this thing needs plugs, wires and such.

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    Re: Gas mileage in the CJ's

    hmmmmm whats gas mileage????? on a good day with everything running as it should i get about 5-8 mpg with a 383 stroker th350 trans 2300 -2500 rpm stall 4.88 gears and 38 inch tires
    Attached Thumbnails Attached Thumbnails Gas mileage in the CJ's-part951289397864791.jpg  
    my jeep is dead

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    Re: Gas mileage in the CJ's

    the wife's stock 93 (4.0, auto, 3.07 gears, stock tires) gets 15ish in town and 19ish on the highway at 65-70mph

    my almost stock 87 (4.2, auto, 3.07 gears, 31" tires) gets 13ish in town and 17ish on the highway at 65-70 mph


    if we do 60-65mph, we get a solid 20-21mpg out of both on the highway
    I love my old jeep.

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