mileage. the harder i try the worse it gets...

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I always wonder about the guys saying they get 20 mpg with a 318....

I have a 92 Dakota pickup and it has the magnum 318, 3.91s , auto tranny with OD......I generally get about 10-11 around town and 12-13 highway.....My 03 Durango has the 360.....same gears, auto tranny with OD...same gas mileage.

I didnt bat an eye when I saw that my fish with a 318 (cam, edelbrock carb and manifold, headers) gets the same mileage.....I am always "into it"......

But seeing someone saying I should be getting 20 mpg makes me wonder if I am doing something wrong.

That said, my motorcyle gets around 30 mpg (jets, pipes)......other guys who have the same bike as me claim to get a minimum of 40 mpg.

Go figure.
 
i have seem 15-17 with the cam and a stock 2bbl carb. the carb was leaky and rebuild did nothing so i swapped the intake and carb hearing that a 4bbl can get better mileage than a 2bbl. but no matter how i drive it its the same 10 - 11
 
The ones getting 20 mpg are the ones we blow on pass on the freeway doing 75, while they are doing 55...I wounder still if they really are getting 16 and thinking they got 20..maybe their speedo is off and they thought they were going 60 and we were going 80

Good point about the carb springs, and yes the idle screws should not be out so far.
 
Been many years, but i seem to remember a 2000 mile roadtrip in my 68 A108 van, 318 2barrel, 3speed stick, 3.55 rear, about 1200lb load, 75mph average netting real close to 20mpg... The other side of that was my 77 D150, 318 2barrel, 727, 3.55s in a 9-1/4 rear, never seemed to do better than 12 around town and 15 on the road, load had no bearing on mileage, could be empty or have 2000lb in the back...
 
yes, got 20 mpg in my 72 demon with a real worn out 318 that I pulled from my 67 Belvevere. That was on the interstate doing exactly 60 mph. This was back in the days when gas was gas (no alchohol). And I tuned and tuned that car. (still had the points!).
THis was on a trip from FL to NJ up I-95. BTW, it had a stromberg 2 bbl, single plane intake (factory!) a 727 and 8 3/4 with 2.94 gears. I could not believe it myself at the time! I remember wondering why the needle was not moving on the gauge;though it was broke or something. I think the cool air (Oct), and you know the thick air (low elevation)
and the constant and exact speed helped. That and the motor was seriously on the loose side (worn out, low friction I call it). I had ripped out the rear seat and stuffed all my belongings back there and packed up the trunk so, light weight of the demon had no effect on things. Oh well, those were the days.
 
You can bet the Edelbrock carb is so rich. Should put car on a exhaust gas analyser. That will give you your answer. Will check it for you if you want to drop by.
 
rigrunner said:
i have seem 15-17 with the cam and a stock 2bbl carb. the carb was leaky and rebuild did nothing so i swapped the intake and carb hearing that a 4bbl can get better mileage than a 2bbl. but no matter how i drive it its the same 10 - 11
Click to expand...

Are you talking around town or cruising on the hiway?
 
wow....Now i know why I took the edelbrock carb off my 340...the holley carb does everything better and restarts easy when hot 15-17 mpg if kept under 65 mph....
 
clipped a few coils off the springs. seems to smell less rich under accelerations but the idle screws still are 2.5 turns out. leaving in a bit to take a west coast run wont be able to work on it anymore for a week or so. thanks for all the replies.
 
clipped some coils of another set of springs has a little surge so thinking to much. havent driven enuff to fill up yet and now finding out weve had someone stealing gas from the neighborhood. maybe thats whats happening? been busy with my truck project and work and still havent ordered the calibration kit but planning to very soon. also my d100 has a stock early 70s 318. thinkin of upgrading should i go smaller cam and something besides the eddy carbs? its a 3speed man with 355 geared 8.75.
 
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