[70 bird]

My firebird back in 1996 when purchased. 400 with 11-1 compression, turbo 400 with 4k stall converter and 4.88 gear. Maybe 450 hp. about 6mpg.

Today 462 8.7-1 compression summit 2802, turbo 400 3k stall and 3.08 gear + borg warner s475. 700+ hp. about 13 mpg.

[Tom Vaught]

Originally Posted by 70 bird

My firebird back in 1996 when purchased. 400 with 11-1 compression, turbo 400 with 4k stall converter and 4.88 gear. Maybe 450 hp. about 6mpg.

Today 462 8.7-1 compression summit 2802, turbo 400 3k stall and 3.08 gear + borg warner s475. 700+ hp. about 13 mpg.

Braggard! Your stuff runs good for sure Mr 70 bird.

Tom V.

Still need to do lunch at the Mac-D one day before Christmas.

[Qball]

My '76 Lemans Safari Wagon (400 2 bbl th350) got 8mpg.

[scld1354]

Originally Posted by 72projectbird

94 F350 351w on 35's gets around 9mpg. Good thing both tanks work!

'93 Bronco w/ a 5.8 (351), E4OD, 3.55s with 30" tires got around 12mpg unloaded, got 9mpg from CO to CA towing a 65 GP.

[Jagtec1]

I got about 8.6 MPG on my drive to Atco with the wagon last week. 3.90's and 3000 RPM at 60 mph will do that.

[Skip Fix]

The 460 Truck we used for farm calls when I was in a horse practice in CA.

Second was my wife's '73 454 Chevy truck. 9mpg , 7 mpg towing the horse trailer. And it only had a 20 gal tank! You sure did not even know the horse trailer was back there and I also bet it was almost as fast as my '78 with the stock motor and 2.56 gears. Moving to CA and back to Texas there were some stretches that we were on fumes.

[hurryinhoosier62]

Originally Posted by 400 4spd.

'72 Grand Prix, it gets an average of 10 m.p.g. My Yukon may have that beat by a mile or two.

Really? Mine AVERAGED 15 mpg.

[72projectbird]

Originally Posted by scld1354

'93 Bronco w/ a 5.8 (351), E4OD, 3.55s with 30" tires got around 12mpg unloaded, got 9mpg from CO to CA towing a 65 GP.

That GP is a big car to be pulling around

Once the snow starts flying and I have the blade on it the mpg's go out the window.

[Kenth]

My 1970 Judge 455 .030" 744 cam TH400 3.55:1 225/70x14 got 10.5 - 12.3mpg

My 1966 Tripower 400 .030" 068 cam TH400 3.07 215/75x14 got around 16mpg.

[Cliff R]

We rented a U-Haul 24' truck once for a move. It was brand new and we put the first miles on it. It had a Ford V-8 engine in it, pretty sure it was 370cid. Biggest TURD I ever drove, had no power whatsoever, and got between 3 and 4 mpg driving from Ohio to Virginia........Cliff

[A.W.Dille]

Originally Posted by dataway

78 Chevy full size PU, 350 4bbl auto, original engine. Would get 12mpg highway, city, 80mph, 30 mph, empty, full, uphill, downhill. You could throw it out of a plane and it would still get 12mpg.
It defied everything I learned about physics and the conservation of energy.

JohnnyB

I'd love to see 12 out of mine. If I'm pulling my two horse trailer mileage drops to about 4-5. And with two round bales of hay it drops to around 7 (1800lbs total). I run ethanol free gas and with a carb rebuild last year and a recent tune-up best it has gotten has been ten. And that is with a 2.76 rear-end.

[dataway]

Originally Posted by A.W.Dille

I'd love to see 12 out of mine. If I'm pulling my two horse trailer mileage drops to about 4-5. And with two round bales of hay it drops to around 7 (1800lbs total). I run ethanol free gas and with a carb rebuild last year and a recent tune-up best it has gotten has been ten. And that is with a 2.76 rear-end.

If it's an auto ...change that fluid, filter and modulator. I think mine was around a 3.2? rear. Still baffles me to this day how nothing had an effect on the mileage for better or worse. I figure the whole engine/transmission combination was so inefficient that there was nothing you could do to get it to be less efficient ...so it ran consistently at it's peak inefficiency of 12mpg at all times If someone could have studied and reversed engineered ..and by that I mean engineering it exactly the opposite of what it was, you could probably build a 50mpg truck

JohnnyB

[geeteeohguy]

'69 Suburban with a 350, 4bbl, TH400 and a 3.73 rear end: 6-8 mpg.

[The Boss]

I'm waiting for somebody to get on here who once piloted the mobile launch platform for NASA - 125.7 U.S. gal/mi - now that's some ****ty mileage!

[77 TRASHCAN]

My trash truck, 1985 F150 351W HO (it's a ho, for sure) The HO's have holley 4 bbls, I'm guessing 585 cfm. Bought it from my former employer for about half of what it would scrap out for. 8 MPG highway, w/ 3.00:1 gears. Oil consumption is close to same...

In all fairness, a fellow Pontiac enthusiast had an identical equipped 84 that got 13-15, because it was in much better mechanical condition...

[Sirrotica]

78 Ford school bus that I bought and ripped all the seats out of for use as a moving truck. Also 370, 5 speed, 2 bbl. Holley. Empty or full, flat or hilly, it was gutless and a pig on gas, advancing the timing helped a little bit it was between 5-6 MPG from Memphis to Erie PA and return. Then I used it to move from Memphis to Marysville OH. Only thing good about it is I bought it in 2001 for $1000, and scrapped it in 2013 for $1350.

My 69 GTO 400, T400, roller cammed, 4.33 geared, 10.5 to 1 comp, reworked Q Jet, was about the worst car I've driven, on a good day maybe 7 MPG on the highway, 5 or less, if I was driving it hard in town.

In comparison a 76 T/A, T400 with a 455, 268 HE C/C cam with 3.23 gears 9.5 comp. reworked Q Jet, about 15 on the highway, 10 in town.

My K3500 dually, which I looked for a long time to find with a 6.5 Turbo diesel, 4L80E, 4.10 gear gets 16-17 unloaded combined city and highway unloaded. Towing my 33 ft, 7,000# fifth wheel camper gets 10.
I absolutely did not want one with a 350 or a pig block, 454 because, 1.) It's a chevy 2.) Terrible mileage, lacking in torque compared to a diesel.

My 88 IH 1600 16,000 GVW, ex U Haul 5 speed 4.56 axle with a 7.3 N/A diesel got about 12 average on the highway, unloaded 1 way, loaded return.

2005 GTO, 400 HP, 364 cu. in. 6.0L, 3.42, 4L60E, averages just over 21 MPG combined just like it came from the factory.

[Ben M.]

Originally Posted by Cliff R

We rented a U-Haul 24' truck once for a move. It was brand new and we put the first miles on it. It had a Ford V-8 engine in it, pretty sure it was 370cid. Biggest TURD I ever drove, had no power whatsoever, and got between 3 and 4 mpg driving from Ohio to Virginia........Cliff

I rented the same type of truck 2 years ago and it was almost brand new as well. Got 6MPG over a 75 mile period and was gutless and governed extremely oddly making driving it a real chore. So not much has changed regarding those U-Haul trucks...

[Bob Crueger]

68 unimog 10mpg's on 38's with 7.86 gears. With a 2.2 litre straight 6.

[screamingchief]

Hands down the worst mileage of any vehicle I've owned is my current DD.

It's a '88 F350 DRW with a 460 & C-6 trans w/3.55 rear gears.

Average mpg is right around 6 mpg give or take say 1 mpg or so.

And yeah,as other's have said,does'nt matter if it's empty or fully loaded.

All in all it's a damn nice truck,really do love it,but nodoubtaboutit the mileage is absolutely abysmal.

FWIW

Bret P.

[zeebo]

Originally Posted by dataway

78 Chevy full size PU, 350 4bbl auto, original engine. Would get 12mpg highway, city, 80mph, 30 mph, empty, full, uphill, downhill. You could throw it out of a plane and it would still get 12mpg.
It defied everything I learned about physics and the conservation of energy.

JohnnyB

lmao..gawd amen to that..i had a 76 chevy pu with the 350 2bbl...3.40 ratio..about same mileage going 40 or 80..no diff...wow..someone who has been there!