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Mileage

mountain33

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Have 71 RR stock 383 4160 Holley carb auto trans. Currently getting 9 to 10 mpg. Car starts runs great. What can i do to get better mpg? Car is all original as far as i know.
 
I squeezed 12 outta my 68 runner on the way home from Carlisle with a 4 speed and 3.55 gears. I thought that was amazing for that thing. I'd say you are doing ok.....drive the prius if you want a bit better mileage???? :D:D
 
Didn’t mention gears. This is like the Hellcat guys trying to save money on oil.
 
I'm assuming that you are taking about highway gas mileage. The problem with these cars and gas mileage is that they run at a higher RPM at highway speeds. if your pushing your big block over 3000 RPM on the highway you will never get good gas mileage. the trick is to slowdown. but like most of us we don't like to do that. I am getting 14MPG with my 512 and i am cruising 70-75MPH. I have fuel injection, which can help and i have overdrive w/lockup converter and i still run a 3.73 gear.
 
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I could get 15 mpg highway out of my 70 383 4sp Roadrunner and 14 mpg in my 70 440 auto GTX.

Around town and getting into the pedal, probably closer to 10 each.

To get better gas mileage, I drive my wife's Prius. :rolleyes:

In your case, I would look into overdrive auto or a 5 speed manual.
 
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This will do just a little over 17 mpg if I drive sensibly,4 spd,3.54 Dana,the black one around 15 mpg.

P5110151-001.jpg Picture 226.jpg Picture 156.jpg
 
Have 71 RR stock 383 4160 Holley carb auto trans. Currently getting 9 to 10 mpg. Car starts runs great. What can i do to get better mpg? Car is all original as far as i know.

What gear?
What transmission?
What tires?
What kind of driving?
Was anything done to the motor, and if so, what?
What torque converter?

We'll need this to know if your current gas mileage is about right or not.

Better gas mileage comes from better tune. After that, different gear, cam and EFI.
 
I didnt buy my Bee for mileage :thumbsup:,put a 2 barrel carb on it and 323s in the rear.:poke:
 
9-10 mpg sounds about right to me.

Depends on what it is. I've had 340s, 383s, 440s, and 508. Cams and power levels of all sizes. None got less than 11 or 12 mpg. No reason a stock-ish 383, if that is what this is, couldn't get 12+ mpg around town, and 15+ on the open road. But the details matter.
 
I think I got about 14 or less on the highway when I bought my Road Runner. It has a 750 Eddy and was rich as hell. I leaned it out a bit with new rods and jets and I now get about 16.........with a 4 speed and a 3.23 rear end. 2800 RPM @ 70MPH
 
Lots of variables as mentioned throughout the thread. I currently have an automatic with a 440 and 3.91 gears and get around 10 mpg. I will say that long ago, I had a 383 4bbl Challenger RT, 4 speed with 3.23 sure grip and averaged approx. 14 around town & 17 average mpg on a trip to Florida and back driving around 70 mph where I could. But remember, that was long ago, when stuff was made in USA and quite a while before they changed the water, LOL. :D
 
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Maybe he doesn't know D is for drive. But dam my one ton with 4:56 gears gets almost that.
 
What gear?
What transmission?
What tires?
What kind of driving?
Was anything done to the motor, and if so, what?
What torque converter?

We'll need this to know if your current gas mileage is about right or not.

Better gas mileage comes from better tune. After that, different gear, cam and EFI.
727 trans, 14 inch cooper cobras, only drive it to shows within a 100 miles of home. Nothing done to motor. No idea about convertor or rear. I would have to see if its listed on the build sheet that was with the car.The car is exactly like it came out of factory. I'm second owner. Car has been sitting in garage for last 40 years. I got it last fall. Just wondering if there was an easier way to increase mileage or like the other guy said just accept it and go with the grin factor.
 
727 trans, 14 inch cooper cobras, only drive it to shows within a 100 miles of home. Nothing done to motor. No idea about convertor or rear. I would have to see if its listed on the build sheet that was with the car.The car is exactly like it came out of factory. I'm second owner. Car has been sitting in garage for last 40 years. I got it last fall. Just wondering if there was an easier way to increase mileage or like the other guy said just accept it and go with the grin factor.
The gear question above is key information needed. Assuming a 3.23, everything else stock-ish, it should be getting 13 to 14 mpg around town,and 16+ on the road at 60 mph. Sounds like it needs a good tune.
 
I only get 6mpg after a Dyno tune on my mild 451 build with 727, 3.55 gears, and 28” tall rear tires. I’m jealous! One thing I still need to do that does affect mpg is hook up my distributor vacuum advance and dial that in correctly which should help my around town mpg off idle.
 
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