/6 Mileage ?

I am freinds with a guy who is old enough to have bought early 70's cars new. He is real decent and honest.

So I ask him what his Duster gets for MPG, and he says that the 225 automatic car got basically 30 MPG. He said his mid 60's early A with a 3 speed got upper 20's..........

This seems to be awfully optimistic to me, but I am not sure. No experience here.

Anyone want to chime in with their experiences?

Curious Rob here!

That seems to be very good mileage, but maybe hes' a very conservative driver with a very light foot. Mike

It depends on what it is in and what trans it has. The automatic cars don't get the same mileage. I got between 17 and 22 MPG with an 84 /6 4 speed truck. I've had a /6 auto 72 Scamp that only got 14 MPG.

When they were new, I could understand the mileage. I ran across an old add that claimed the then new '75 Toyota Corrola was advertised @ 38 mpg's. Today, few cars top that.

As time goes on, the car becomes worn and can no longer produce the power it used to even though it may perform strongly. My previous slant six gave absoulutely poor mileage to the point that I don't mind driving and paying for the big blocks consumption. (LOL, 3 times the HP doesn't hurt ethier.)

30mpg......I don't think so. Mabey mid 20's to no more than 27 was probably possible, but who on earth does not drive their /6 with it to the mat when trying to accelerate around town?

I used to get 25 commuting 70 miles a day. This was in my wagon with a worn out slushbox. And I never tuned it up, just drove it till it kinda died.

I have always heard 23-24 on the high end and 18-20 was the average.

I've got a 1967 Valiant ute (pickup) which was driven 500miles to a chrysler show at easter last year.It's a slant 6 /904 and retuned 24.5mpg.This year same trip at easter but with a holley 600vac 4bbl fitted returned 23mpg.

When I was a kid,I had a 66 Dodge. 2 door post,225/,auto. (Wish I still had it) 24-25 mpg hi-way. When I got out of school,bought a 72 Duster,318-auto. 22-23 mpg hiway. I started pumping gas at my Dad's station,when I was 10,and prior to the smog stuff of the eary 70's,20 plus mpg,even in big cars,was not uncommon.

The below quote came from Moparstyle.com.

1975: The new Feather Duster and Dart Lite were introduced. They got 24 city/36 highway using their Slant Sixes and Overdrive Manual Transmissions.

I think the first/only time i checked my valiant i got 23 mpg, but that is canadian.

I guess there are so many variables once they get old that it is almost a pointless question.

I was just curious as to what others have come up with.

I know that my tow truck gained almost 3 MPG and a whole bunch of power with an aircleaner change............gotta check that!


Thank you, ROB

My first brand new car was a 74 AMC Hornet with a 232 6 with a 3 speed manual. My roommate purchased a new 74 Dart Sport with a 225 and automatic.

The AMC got low 20's around town and mid to high 20's on the hiway. This was a time when gas mileage was a very high priority because of the gas crunch that only allowed you to purchase gas on alternating days. Once on my way home from Hartford to Boston I kept it at 55 and drafted semi's any chance I could get and I was able to get the mileage to 30, but that was not something you could expect.

My roommates Dart Sport got about 2-3 mpg less than my AMC which at the time we attributed to the auto tranny.

Also, in the late 70's I purchased a used D100 short bed pick-up with a 225 / 904 combo. This truck got about 12-15 mpg around town and 17-19 on the hiway.

in high school i had a swb 73 van with an 85 /6 904 and im guessing 3.73 or 3.91 gear. it had lots of go and got around 20mpg. i thought that was good for a beat up old van and a heavy foot

We have a /225 in the Duster now and it gets about 14-15 mpg,doesnt matter if its on the freeway or around town.Probably because like 9sec said the foot is to the floor all the time.Just another reason we decided to go to the 360 !!!

Bob

my slant wagon 3 speed on the tree got 13 mpg or so, how horrible. well it was pretty tired and a 75 motor :wack:also had no power at all

My 72 /6 Scamp gets around 22 mpg and it's got 138K on the odo and a pretty hefty intake leak.

I just drove my 66 Dart 225 to a show about 110 miles away. Drove hard (75+/-) the whole way. Got 19.7 MPG.
Joel

I got 17mpg out of my '81 D150 with a manual trans.


Chuck

i got 19 mpg out of my /6 auto duster. i was kind of dissappointed seeing how i got 14-15 out of a 360 1 ton dodge with serious meat on the wheels.

ok slightly OT but i had a 1 ton dually ext cab with a 400. it got 10 empty, and 12 -13 with a good load (car tools heavy trailer ect) :wack:

I had a 1975 d200 dodge pickup with a /6 and 727tranny. I got 14mpg from oklahoma to nebraksa with my foot on the floor the whole way.

Drove a 64 Valiant 225 with a three on the tree for 84,000 miles. Kept track of all maintenance and all gas consumed. In 84,000 miles it had averaged 20.1 MPG for every mile it went and gallon it consumed. The best I ever saw was 27 mpg the worst, 13. Those below zero mornings where it idles for who knows how long because a slant six never warms up tend to get it close to the 13 mark. 22 to 25 was my normal highway expectation.

The 225 Valiant convertible I have now with a 225 and 904 has averaged 17 but it's almost all around town and I haven't driven it very far. It's probably been run on the driveway at least once for every time I've actually driven it on the street.

Quoted from Allpar:

"The Feather Dusters were made in 1976, with an aluminum inner hood, trunk bracing, bumper brackets, and intake manifold; economy carb and distributor calibration; large exhaust system; tall rear axle ratio; and either 3 speed auto or 4 speed overdrive manual trans.

Their gas mileage was great for their day, and even for the present, given their size: 24 city, 36 highway."

30mpg highway from a good running /6 doesn't sound unreasonable to me.

I heard that the Ford model T averaged 25mpg. And the average car today gets 18. Tell me why that is. I think it has to do with all the extra crap put in.

Yeah, but a model T made about 25 horsepower and would not run 50mph dead wide open... lol.

Yeah but it got that for mileage when machine work was in the dark ages per say, along with low tech spark control. And it still got that mileage. Computer controls, emission controls, speed controls, etc..

I haven't figured any figures yet but the 73 dart custom 4 door I just picked up has a 225 with a 1 bbl holley bone stock with a rebuilt carb and it is getting better mileage than my girlfriends 93 mazda lx with a DOHC 1.8 or 1.9 or whatever it is.

When Im done with my 27 T I will be lucky if it gets 2 miles per gallon with a beer keg for a gas tank LOL.

My '69 valiant 4 door gets 24 mpg. highway at the speed limit. It's a '75 225 auto stock with 2.76 gears, holley 1 bbl, electronic ignition, and a good tune up. I've had quite a few /6 cars and trucks over the years, and that's typical i've found. Nothing is good on gas if you put your foot in it! The best I've seen is a '82 Miser 225/6 4 spd od. truck that got 30 at highway speeds that we went on a long trip with. I drive my valiant 800-900 miles a month! Subtract 15% for U.S. coversion! They are a good, reliable engine combo if you don't beat on them and take them for what they are,I bet the dart lite would get 30 mpg. U.S. if driven right.

I have a 73 Dart Sport with a /6. On the HWY running at approx 60 mph and taching at just over 3 grand I get 220 miles per tank!!!! Approx 15 MPG!!! If I drop in back to 25/26 on the tach hwy I gain about 60-70 Miles per tank. This is the reason the 360 is on the engine stand, soon to go in!!!

Bryan

I have a 73 Dart Sport with a /6. On the HWY running at approx 60 mph and taching at just over 3 grand I get 220 miles per tank!!!! Approx 15 MPG!!! If I drop in back to 25/26 on the tach hwy I gain about 60-70 Miles per tank. This is the reason the 360 is on the engine stand, soon to go in!!!

Bryan

Boy, THAT'LL help your mileage!

Boy, THAT'LL help your mileage!

Forsure...LOL! No way it will help my mileage... but it should stop the scooters and mopeds from beating me from stop light to stop light!!! LOL!

this past week, i averaged about 17mpg mixed highway and city driving in my 66 with a 225/904

I heard that the Ford model T averaged 25mpg. And the average car today gets 18. Tell me why that is. I think it has to do with all the extra crap put in.


safety requirements have made cars heavier and heavier. (well not as heavy as some but still) add that with a small engine and look what you get.
plusthe suvs are bringing that down im sure. im looking to get a 74 4 door dart for a dd instead of my protege that gets 35mpg, id rather DD a dart. :)

My 73 dart with a super six and auto got 22 mpg highway and 16-17 city with my old motor that had who knows how many miles. Have not checked it with my fresh motor.

My 85 stone stock d150 gets 18 around town, 22 mostly highway, and 25 all highway. It has a one barrel and a 4 speed OD.

just checked mine. it got 23 mpg...canadian