304 fuel mileage

[mx racer 904]

Just wondering....I think my mileage is really bad but not sure....i think it is pretty stock( i can run about 65 easy on good road)....i think it might have been in 4Hi or something....I got about 8 or 9 MPG...how is that?

 

[SteelHeadz]

LOL, that's what i get on my 360 AMC with some edelbrock upgrades. It's got a lot to do with my big tires and the stupid stock gears on it. If your unsure of the transfer case setting, jack up all 4 wheels and lock your front hubs. See if all the tires spin when you engage it in gear.

 

[Saddle Tramp]

Looks about right to me.

 

[dave123]

mine 75 304 with 31 inch tires gets about 10

 

[jps4jeep]

rebuild the carb and tune the motor... might be able to squeeze another mile or two out of it, but thats about all.

 

[expertshooter22]

sounds great to me to actually, my newly rebuilt 258 w/33's gets 8 or 9, back then they sure weren't worried about fuel conservation, when gas was 89 cents a gallon!

 

[Crazy4diesels]

If I recall, my friend's 79 w/ a 304 got about 10-12 MPG but it was driven mostly on back roads. He had a four speed and about 31" tires at the time (I don't remember the final drive gears) - John

 

[kingaircj]

????? I get 18 mpg in my 304. I have a Motorcraft 2100, T15, 3.73 gears with 33x12.5. What did I do right?

 

[Keith__C]

Chances are you have hit the magical formula for your combination. Real fuel economy is not determined by keeping the RPMS low. Real fuel economy is made by keeping the engine running in the sweet spot of the RPM range so that it never has to work or struggle to maintain the RPMS you are running at. Every motor has a sweet spot when you find out what RPM it is at, then match your final drive at the speed you drive most to that RPM and you're fuel economy will skyrocket.

 

[bluerubicon]

sounds low to me.....I got 12-13 from a slightly hot 401 in a 81 scrambler

 

[mx racer 904]

I think it will be higher....I just cleaned the carb and it seems to be running better...plus I am going to go get a tach because I think I am short shifting to much....

 

[Collin the Hen]

I was getting 13 to 15 mpg on a 16000 mile reman 258. Turns out I was putting it in overdrive at 55... 1400 rpm. After I started working on it, I realized that 2100 was where I should have been cruising. With my old gearing, at 2100 I would have been going 82mph! I'm in the process of getting 4.10's installed...

Screw 2.73.

 

[gommba]

I get about 16 mpg on my '79 CJ7. The new JK's get about 17. Things haven't changed much in 30 years.

 

[mx racer 904]

well after cleaning the carb I got 13 and that was included leaking some from a fuel leak I have in another thread...some reason it like overflows out of top somewhere i cant see

 

[SteelHeadz]

This thread is making me go in depression. 16mpg? what?:bomb:,18? huh? .ooh i got an idea, drill in my backyard and see if i can find oil and start my own oil company and support my Jeeps alcohol dependency. :roll::???:..

 

[prof_fate]

Things that will affect mileage (for the worse)

A soft top will eat 2 or 3 mpg compared to a hard top (wind resistance)
A lift will hurt mileage, mostly do due to increased drag under the vehicle. Almost always a lift will include larger tires and wheels - more rolling resistance and more weight (200 to 300 pounds more weight in the wheels and often another 100 pounds in the lift kit over stock)

My 90 YJ with a 3" lift, 32" mudders, 305 4Bbl chevy 4 speed auto and 4:10 gears averages about 11 mpg If I baby it and run naked it does a bit better, but highway speeds with the top on it can get me down into the single digits.

I'm planning a long trip next year and am starting to look for some near-stock wheels/tires in the hope I can get 15 on the hiway when I'm done.