James Clews
Well-Known Member
No Bewy! Just using the imperial gallon so yes that 15 mpg is even lower in US gallons.
Gas mileage 225 Slant 6
- Thread starter Analogprincess
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BillGrissom
Well-Known Member
I bought the Dart used when a Senior in College, in the days of the song, "I can't drive 55" (federal speed limit). Owned it for 18 years until stolen. Later, speed limits crept up, but I would usually limit to 65 mph on trips. 22 mpg was on the highway.
Lol,
yes, it's smaller. Put a pinion in with 5 fewer teeth, and You'll be able to feel Your mileage improve, as well as do 75 in a 55 w/o ever getting ticketed.
1967DartSwinger
Active Member
I’m curious then,what would a 273,a 318 and a 360 with torqueflite get if driven normally? I’ve heard others say the V8’s do quite well if you keep your foot out of them
I had a 71 Dart with a mild 360, 904 and 3.23 gears bump 20-22 when I drove like an old man, which wasn't often.
1967DartSwinger
Active Member
It was with a Thermoquad, of course. Headers and the Crane Magic cam.
446acuda
Well-Known Member
With the mileage all are reporting, I can't see how a Feather Duster or Dart Sport Lite with a /6 and A833 OD could come close to the advertised 24 mpg city and 36 mpg highway.
I have called BS on the 24/36 several times
Charrlie_S
Well-Known Member
The biggest factor in getting good fuel mileage is the nut behind the wheel.
Slantsix64
Well-Known Member
16-18 mpg, do a tune up adjust your valves, check your timing.
i get 20-22mpg mixed, but my motor is not stock, 9:5 compression 500avs dual manifolds 4 speed with 2.93 gears, 12 degrees initial 16 mechanical 22Vcan for a 50 total.
i get 20-22mpg mixed, but my motor is not stock, 9:5 compression 500avs dual manifolds 4 speed with 2.93 gears, 12 degrees initial 16 mechanical 22Vcan for a 50 total.
76Scamp
Well-Known Member
I'm about the same as Stretch here. I have 40 mile commute that is primarily highway 60-75mph and the last few miles through town at 45-50mph. I average 25mpg. Whenever I drive across the state to see my parents I get 32mpg maintaining 70 the whole 180 miles. Car is a '74 Dart Sport. Engine itself is a stock, 30k mile survivor; has a header, dual 2.25" exhaust, Clifford intake with Weber 38 2bbl. Trans is the original A230, 2.73 gears, 27" tall tire. Took the timing from whatever the factory had it set at and turned it all the way up. Maybe one day I'll check where it is. Every car is different; my '76 Scamp that started me into these cars only got 16mpg. That one was an automatic car, unknown gear, stock tire height and almost 200k miles when I sold it. But, that one was a factory air car and it worked; 9-12mpg when I used the a/c. Obviously, I just drove with the windows down.I daily drive my 73 Dart (Known as the Shart because Stretch has a Dart).
I live in a very rural area of upper Michigan so my daily commute is a combination of back roads and 2 lane highways with 55 M.P.H. being the max speed. Its about 25 miles to work with two small towns to slow down through. I average 21 M.P.G. back and forth to work and on a recent road trip (200 miles round trip on two lane highways) I averaged 29 M.P.G..
My car is a 225/904 with unknown gears, 4 wheel manual drums and 14 x 5.5" wheels. I rebuilt the carb, adjusted the valve lash, did a basic tune up, replaced all the vacuum lines and replaced the intake/exhaust gasket. I set the base timing at 12 deg. BTDC. I custom bent a 2 1/4" dual exhaust system with two cheap reverse flow "turbo" style mufflers. I made a new down pipe and installed a "Y" to split to the duels. I also set the wheel alignment at .5 deg. negative camber (both sides), as close to 3.0 deg. positive caster as I could get while keeping the camber at .5 negative, and set the toe at 1/8" in.
I have collected the parts required to convert it to a A833OD this winter. I just need to rebuild the transmission and find a flywheel. It will be interesting to see what the OD does to the fuel mileage.
Every engine is different & all have a 'sweet spot'. It is quite possible to have a larger engine get better mileage than a smaller engine if the bigger engine is operating in it's most efficient range.
Well Elvis has left the building, but I'll join the fun anyway.
When I commuted to college, my '75 4 door Valiant got a pretty consistant 17 mpg in a mix of suburb, highway and city driving. It didn't really do better than that when I commuted to work, but that was at least somewhat attributable to the driver...
My '74 Nova with a worn 250 cid straight 6 got around 16 mpg...
A '68 Barracuda notchback /6 with a 225 got 21 mpg on the trip from Chambersburg Pa to North Jersey. Didn't get to drive it to work long enough to establish commuting mpg but it was better than my mid '70s a-bodies. A lot peppier too without the stupid OSAC.
(all of the above cars had automatic transmissions)
When I commuted to college, my '75 4 door Valiant got a pretty consistant 17 mpg in a mix of suburb, highway and city driving. It didn't really do better than that when I commuted to work, but that was at least somewhat attributable to the driver...
My '74 Nova with a worn 250 cid straight 6 got around 16 mpg...
A '68 Barracuda notchback /6 with a 225 got 21 mpg on the trip from Chambersburg Pa to North Jersey. Didn't get to drive it to work long enough to establish commuting mpg but it was better than my mid '70s a-bodies. A lot peppier too without the stupid OSAC.
(all of the above cars had automatic transmissions)
They didn't. I won't expound any further, but the slant 6 never got 30 plus. Somebody's poor at math if they say otherwise, I don't care who it is. They just are not that efficient.
Yes and doing correct math. lol
Kind of off topic, but what was your strategy to get to 9.5:1? .100” off the deck and head?
Charrlie_S
Well-Known Member
I have a 1964 Valiant 170/3 speed/7 1/4, that was built for fuel economy. It will get upper 20's mpg. Problem I have is too much compression and too little cam. It is true 9.5 CR, and unless I have the timing "backed" up it pings. I need to work the distributer some more.
PS: I do not believe any factory stock slant six car got "real world" MPG of over 30 MPG. Upper 20's maybe.
PS: I do not believe any factory stock slant six car got "real world" MPG of over 30 MPG. Upper 20's maybe.
I agree. They were hard to get 18-20.Now under the right circumstances yes they can do better.
For the average Joe, not us that tune to the nth-degree . Also terrain plays a part.
You live in the flat lands ? Mountains ? maybe just hilly ? Our 70 Dart 225 auto on a good day was 14 16 at most. That was in the hills of southern Pennsylvania .
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FISHYPETE
Well-Known Member
I get 17 mpg in my 72 FuryIII 360 2bl on cruise control set at 70mph original unrestoeed
I had a 170, not stock, in a 64 Barracuda 4 speed that would get high 20's all day long on the highway. Probably hit 30 mpg a couple times. And I can do math.
Slantsix64
Well-Known Member
yep straight BS, motor was made in 1959 the best i could see those feather dusters getting is 24-26 Highway.
i milled only the head .120
Charrlie_S
Well-Known Member
As you said "not stock". Mine is not stock either. I stated that I did not believe any stock slant six ever got "real world" over 30 mpg, and I stand by that statement.
PS: A 170 was not available in the barracuda from the factory. 225 was the "base" engine for the Barracuda, and 170 was base engine for the Valiant.
PPS: I had a 170 in my 66 Cuda, but I put it in. Removed a not running 360. Car was born with a 273 2bbl.
I saw that, I was just chiming in that 30 mpg was possible in a slant. My 170 was built for speed, don't laugh, and to try something different. I had just Built a 170 Ford for a friend in an early Falcon. My 170 replaced the HP 273, also not stock, when gas took a nose dive in the 70's or 80's. Probably came out of a Dart or Valiant, 3 speed manual. I kick myself for practically giving that 170 away in Baltimore, MD.
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