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A 401 CJ
A 401 CJ GRM+ Memberand SuperDork
7/18/21 6:40 p.m.

Just curious what the worst one is.

 

For me, I'm going to cheat a bit because the absolute worst one I've ever seen first hand I didn't own or even get to drive.  
 

It belonged to the gentleman farmer on the next property over from where I grew up.  It was a stunningly gorgeous mid-'70s square body Chevrolet dually.  Three tones of deep blue paint, crew cab (3+3 I think Chevy called it), requisite sprint car wing on the back half of the cab to break the wind before it hit the trailer, and a "built" 454.  This was the early '90's when turbo diesels hadn't come into their own yet in domestic pickups.  Dodge had the 12 valve but  only a few knew about it and it was super anemic in factory tune.  I think Cummins tuned it to run a million miles.  Anywho, this one was supposedly a lot bigger than 454.  "Pushing 500" the farmer told us.  "Built for torque" he said.  But interestingly it had a giant Holley double pump carburetor instead of a Q-jet.  It was the '90's and just prior to the internet when everybody just "knew" Quadrajets were complete junk.  Smarter people had not yet surfaced in significant numbers.  It sounded great through the long tube headers and three inch chrome tipped duals.  Not loud at all but a deep "poof poof poof" you could feel in your bones.  So this guy hooks up his gooseneck horse trailer, puts six or so average sized horses inside, drops the non-locking TH400 into drive and heads to town.  We never saw it again.  A few weeks later my father inquired as to its whereabouts.  "Sold it" the farmer said.  "It'll pull a barn down but I can't run a rig that gets 3 mpg".  Three.  That's berking nuts.

I had a '76 Corvette along about this same time.  I'd bought it from a guy who'd removed the original anemic (I think it was the lowest hp corvette ever sold) 350 and replaced it with a mid-'60's 396 of unknown origins.  The number on the block simply decoded to '1966 Chevrolet 396.  Passenger car'.  It had the requisite speed parts on it and ran fairly well.  I was always impressed with the smoothness of it --it did not have a radical cam.  But for berk's sake did it ever like gasoline.  I could get 12 on the highway but 9 was a more common number.  My dad ran a heating oil and gasoline distributorship.  He let us fill up our cars for free.  Usually.  He finally cut me off in the Corvette.  Said it was eating too much into his bottom line.

Slippery
Slippery GRM+ Memberand UberDork
7/18/21 6:44 p.m.

The worst I had was my '85 MB 500SEL. It would get about 13mpg in the city. 

ShawnG
ShawnG UltimaDork
7/18/21 6:49 p.m.

Wife's 1970 Lincoln Continental.

If it gets 7mpg I'd be surprised.

Tom1200
Tom1200 SuperDork
7/18/21 6:49 p.m.

Our 74 Ford F350; if you pushed it above 75 mph on the highway it would immediately plunge to 4 mpg.

Feedyurhed
Feedyurhed UltraDork
7/18/21 6:52 p.m.

I had a 1999 Jeep Cherokee with a 3" lift and 31" tires. In the winter/snow in AWD I would get 8-9 miles per gallon.  I had a friend at the time with his own business. At work he drove a Chevy cube van with a 350 motor and he would get 10-11 mpg. We would laugh about how bad the Jeep was compared to the big van.

JThw8
JThw8 UltimaDork
7/18/21 7:01 p.m.

79 Ford F250 with a Chevy 400 mated to a T18 and 4.54 gears.   8mpg, city, highway, loaded, unloaded, towing, 8mpg.  But it would pull my house off its foundation if I asked it to.

2nd runner up is current DD at 12 mpg.

A 401 CJ
A 401 CJ GRM+ Memberand SuperDork
7/18/21 7:15 p.m.
JThw8 said:

79 Ford F250 with a Chevy 400 mated to a T18 and 4.54 gears.   8mpg, city, highway, loaded, unloaded, towing, 8mpg.  But it would pull my house off its foundation if I asked it to.

2nd runner up is current DD at 12 mpg.

My father always wondered why more people didn't swap Chevrolet engines into Ford trucks.  He had a lot of trucks and always said that Ford was a better truck but Chevy offered superior engines.  I tend to believe that.  At least the truck part.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/18/21 7:19 p.m.

My '72 T-bird would get 2mpg in the winter.  Most of my driving was trips short enough that the carb never came off choke, plus all the time spent with the engine running while clearing the snow before driving off.  LOTS of iron to heat up in that engine.

SVreX (Forum Supporter)
SVreX (Forum Supporter) MegaDork
7/18/21 7:19 p.m.

1999 GMC dually box van. 
 

Got 4 mpg. I stopped driving it when gas spiked to $5 per gallon and allowed it to return to the dust.  It had a 75 gallon tank. $300 to fill the tank was obscene. 

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) GRM+ Memberand PowerDork
7/18/21 7:20 p.m.

I had a 73 Cheyenne Super 3/4 ton, 454. Turbo 400, non-locking as noted previously on the farmer's truck. I don't know what rear end gear it had, flat out was 89 MPH with big 31 inch tires. 
 

6-8 MPG with a 2 horse trailer and one horse, running 55 on the highway.
 

No trailer, 54 MPH (it's happy place on the highway), I could get 13 if only running on the highway.

I drove it straight through from Hamilton, Ontario to Orlando, Florida. It was a long drive at 54 miles an hour.

pres589 (djronnebaum)
pres589 (djronnebaum) UltimaDork
7/18/21 7:32 p.m.

'64 Plymouth Savoy, 225 slant & a three-speed automatic.  My first car.  I think it got around 20 mpg mixed.  I think my '95 Mustang GT was about equal.

My best mpg car was my '88 Mazda 626 Turbo.  34-35 mpg on the highway easy, 40 mpg on long runs with the A/C off.

Streetwiseguy
Streetwiseguy MegaDork
7/18/21 7:39 p.m.

1969 Ford F1000 with a gas 534, pulling a 40 foot grain trailer.  55 mph was 3mpg.  Canadian.

With the frame stretched and a 20 foot box, it would to 7mpg at 65mph.

I may have stretched the parameters of the discussion a bit.laugh

ultraclyde
ultraclyde UltimaDork
7/18/21 7:46 p.m.

69 F100 with a 2bbl 390 and a 3 speed manual. 11mpg no matter what unless you put the tailgate down. Then it got 12. 

 

I drove a mid 80s F600 utility truck for work with a gas 372 I think it was. Never checked the actual mpg but I'm sure it was mid single digit. Downhill. With a tailwind. 

Appleseed
Appleseed MegaDork
7/18/21 7:47 p.m.

The old man's 95 F-250 with a 460 got 8mph. Loaded or unloaded. 

frenchyd
frenchyd UltimaDork
7/18/21 7:50 p.m.

In reply to A 401 CJ :

1962 Buick Wildcat Convertible. 401 nailhead Buick 430 ft. pds. Torque.  DynaFlow  transmission. 
 Retreaded Bias ply tires.  Pulling a trailer with my Jaguar Race car plus all my worldly possessions. Through  the snow packed Rockies  with chains on. 3 MPG.  That was after a complete tune up just prior to leaving San Diego.  
     The Horrible part was near the summit when I was just about empty they wanted .53 cents per gallon for the required premium  instead of my usual .28-29 cents a gallon.  $13.78 cents!   For a fill!   
      

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
7/18/21 7:53 p.m.
Streetwiseguy said:

1969 Ford F1000 with a gas 534, pulling a 40 foot grain trailer.  55 mph was 3mpg.  Canadian.

With the frame stretched and a 20 foot box, it would to 7mpg at 65mph.

I may have stretched the parameters of the discussion a bit.laugh

The 534 was a beast but definitely built for WOT-forever toughness rather than economy!

 

It really puts the new super duty engine into perspective.

keithedwards
keithedwards Reader
7/18/21 8:00 p.m.

I had a '77 Winnebago Minnie Winnie for a number of years. With the big block 400 Dodge, it would get fractional 7s. Didn't much matter if I was towing my race car. I was thrilled when I logged 8+ mph.

dean1484
dean1484 GRM+ Memberand MegaDork
7/18/21 8:03 p.m.

Surprisingly it is not my H2. 

 

Worst ever was probably one of my old dodge one ton 4x4 pickups I had.  5-6 mpg was what I calculated it at a couple times.  It was used mostly to plow with or do other truck things. 

A 401 CJ
A 401 CJ GRM+ Memberand SuperDork
7/18/21 8:04 p.m.
Streetwiseguy said:

I may have stretched the parameters of the discussion a bit.laugh

Nope.  It's all fair game.  I just wanted to keep it civilian since the military has a bunch of retarded-thirsty stuff 

pirate
pirate HalfDork
7/18/21 8:05 p.m.

In the early 80's had a Winnebago Minnie Winni motor home on a Dodge chassis with the 440 ci engine. Traveling out west we got about 5.5 mpg and I think the best we ever got was about 7.5 mpg that was on secondary roads where speed never exceeded 55 mph.Seemed like it couldn't pass a gas station. 

A 401 CJ
A 401 CJ GRM+ Memberand SuperDork
7/18/21 8:06 p.m.
Pete. (l33t FS) said:
Streetwiseguy said:

1969 Ford F1000 with a gas 534, pulling a 40 foot grain trailer.  55 mph was 3mpg.  Canadian.

With the frame stretched and a 20 foot box, it would to 7mpg at 65mph.

I may have stretched the parameters of the discussion a bit.laugh

The 534 was a beast but definitely built for WOT-forever toughness rather than economy!

 

It really puts the new super duty engine into perspective.

I've seen a few of those.  Not quite as interesting as its competition's V12 (GMC) though.

glueguy (Forum Supporter)
glueguy (Forum Supporter) GRM+ Memberand Dork
7/18/21 8:06 p.m.

No details unfortunately. In my youth I had a autocross buddy with a late 70's Dodge panel van as our tow rig. Two vinyl low backs up front and a lawn chaise in the back with tools, tires and cooler. No AC, boom box strapped to the engine cover. At WOT that thing would do 64. You refueled, hit the interstate and just held your foot to the floor for exactly 2.5 hours before it needed a gas stop and driver change. Awesome memories from that. 

ProDarwin
ProDarwin MegaDork
7/18/21 8:12 p.m.

Driven?  Probably some sort of uhaul I rented.  I'm sure they were around 5ish mpg.

Owned?  CJ7.

Owned and actually driven regularly... 1974 Plymouth Valiant.  Mid-upper teens most of the time.  Maybe 20 on the highway if you were lucky.

jimbbski
jimbbski SuperDork
7/18/21 8:12 p.m.

A 1987 Chevy Suburban with the 454 TBI & Turbo 400 trans. It got 9-11 mpg.  I could eek out 12-13 if I really worked for it. It also got 9 mpg when towing but you didn't know the  trailer was there! 

DWNSHFT
DWNSHFT Dork
7/18/21 8:14 p.m.

1988 Chevrolet Suburban 3/4 ton, 350 throttle-body injection, three-speed auto, 2WD.  11-12 MPG in normal driving.  Didn't even pay attention when the race trailer was hooked up, but it towed well.  Put 105K on it; I don't even want to think how much I spent on gas.

 

I had a 1976 Beetle with a 1974 engine, pretty stock, tiny little Solex carb.  These were supposed to be thrifty little cars.  Mine got 17 MPG no matter what, hooning on two wheels or driving like grandma: 17 MPG.

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