Ladies and Gents I am happy to inform all I have squeezed 20mpg out of my 225 slant six!

Here is a list of things I did to acheive this goal

1. Clean and adjust the carb.
2. got a better flowing air cleaner.
3. proper inflation of tires to 32psi
4. changed my route to less congested roads only added 5 mins to my commute.
5. drove with a lighter foot.

My control measures were:

1. 5.18 gallons of fuel in empty tank ($3.86 a gallon)=$20 bucks
2. 104 miles travled till empty.

It comes out to 20.07mpg so its official!!

Long story short! get a Slant six they ROCK!
Comments questions concerns please lemme hear them! if you got MPG stories or tricks lets hear um!

 

What did you do to the carb? Do we have the same one? (mine is 1976). It was running like crap before I left for school, was gonna rebuild it when I got back.

 

I adjusted the air and bleed and idol screws on the carb turning it all the way to the left and 1/4 turn back and started from there till i was satisfied with the idol. still trying to do something about the lowend bog i get ocasionally when i hammer it.

depending on you slant setup you could be running a holley 1945 1bbl or a Carter BBD 2bbl. you can find out what it is by taking off your aircleaner and looking at the Bowl should be stamped there

 

Neat try but your test has a flaw. There is still gas in the tank when the engine stops. when you add gas to an empty tank, then run to empty again, there is still gas because the pick up tube is not on the bottom. Also you were not carrying a "usual" fuel load.

To accurately check your mileage, fill the tank, drive for a while (doesn't matter how long or far) then fill the tank again. divide the miles traveled by the gallons used and you will have a more accurate number.

 

I know the Tank was empty because i put new tank on last sunday it was bone dry until i put the fuel in it. but your right about the fuel load but non the less i know for sure im right at the 20 mpg mark or even above it! i know i can do better. ill try your method and post those numbers too. and if the tubes not on the bottom and there is still gas in there when the engine stops...that means i possibly did better than twenty! F'n A dude!

 

Nice. I have a Ram with a TBI'd 318. I've gotten my mileage up to 14-15 by paying attention to how I drive and I have my tires at 38 PSI. I could turn the a/c off and get 1-2 mpg more probably, but that's not an option in south FL.

 

Driving better helped me. my mistake was driving the dart like my 99 cobra WOT! yeah id be rockn out the A/C in FL, i'm origanally born and raised in Houston TX so i get it

 

Working at your distributor's mechanical advance could show some gains. Make sure your vacum advance is working properly and hooked to full manifold vacum not carb ported "timed" vacum. These little tuning measures can be easy, cheap improvements.

 

Had a 69 Dart Western Sport Special 30 years ago, with the 6 and an auto. was a great car.. Use to run it around 80mph between LA and Vegas once a year

 

Thanks for the input! This is somthing i overlooked completly thanks for bringing this to my attention!

 

Sweet i lived in San Clemente for like five years and used to make that run in about three and a half four hours pedal to the floor!

 

If this mileage thing is important to you, check out sites devoted to "hyper-miling". or something like that. For more mileage I would inflate tires to the max of the sidewall. Yes, that would affect wear, handling, and lifespan. If you are really into this try a vacuum gauge. You can use this to help modify your driving habits by seeing the "load" on the motor. Now, why dont you fuel-inject it and amaze all of us!

 

I wish i had the time and money to do that. but basically i did this to prove something to someone at work that i could get good gas mileage out of the Dart /6. And i learned about the Holley 1920 1bbl Carb!

But check out my other post when i took it to the track and experienced something else new! who knows where this Dart Custom will take me!?

 

Does your car still have the emissions equipement on it.
Because I am pretty sure you can push your mileage up to around 23-25 mpg with the /6.

 

Yes it does. everything is Original all the way

 

Do you want to keep it all original, or are you considering removing some of the emissions equipement?
Do you know what your State's regulations are?

 

I'll slightly modify it maybe if given a good argument. the outside will be stock for sure

 

I know that around me, N.Y. didn't check, so anyone who knew to, pulled the emissions stuff off.

 

Here in Ohio no one gives a crap, I got my Cobra all decked out and as loud as possible cops just wave lol

 

I knocked a the guts out of my catalytic converter two summers ago....might have given it a slightly different sound, but as for power and gas mileage, it didn't do much. Hard work too!