440 gas millage

Ok boys and girls what’s the best millage you’ve ever gotten out of a 440 past and present? AND how did you do it. I’m planning on using a 74 stock low compression one in my Lil Red truck. I’ll try to make a OD trans work too with the 3.55 rear

14 mpg with my '71 Barracuda, 3.23 gears and Holley 750 vacuum secondary. 3.23 gears.

11 mpg with my '63 330. 505", 850 DP and 3.54 gears.

I have never had a 440 that got more than 15 miles per gallon, but that is probably because I have a heavy right foot.

My current 440, 500 hp and EFI, 4:10 5sp gets about 12 MPG around town driving with some highway thrown in.

I’m sure you know, the low compression is probably gonna cost you some.

Best I got was 18 or so, almost all highway. 1968 Charger, Holley 3310, A-833, 2.94 gears.

Back in1970 this dude that was hanging out at the car spots had a 69 Charger RT claimed he got 18-19 on highway. Claimed he worked for Chrysler and was some type of engineer from Detroit area. Never thought much about what he said until now. Gas millage didn’t mean much then when 260 was $.36 a gallon.

On any of the 440 C bodies I owned . . . best was 15mpg on hiway. Pretty much all had 3:23, stock 70 440 . . .

I can believe it. On a long trip back in the day I got 20 or so one way and then 18 or so on the return

Just as a point of reference, that $0.36 per gallon in 1970 is now the equivalent of $2.84 per gallon today.

So, not as much of a difference between then and now as you would first think.

i'd have to say 10-14 depending on city or highway driving. 3.23 geared b-bodies with torqueflites. i don't believe any of the big numbers; engines are just too inefficient, and who's trying to correct those old speedometers where the factory had them running fast.

I've got a stock '77 440 in my wagon. When it was my daily, 12-14 (mostly city) was the norm. 14-15 was the norm strictly hwy but it did hit 16 a couple of times.

As I've mentioned numerous times, in a truck I used to have I swapped in a stock 440 to replace the truck's 360 and got better all around mileage.

It don't surprise me that much of anything could be at a 360 for mileage. Every one I've had has been a gas sucking pig.

This is proof that there IS such thing as a dumb question.










Just kidding..........kind of.

Ok. What’s the dumb part?

It was many years ago and I was young, but my Father had a 440 powered C-body with a functioning lean burn system. I recall that he was very impressed with that big engine's economy in such a large car. I think he was getting 14 or 15 mpg with it. What ever the exact number was, it was several mpg better than any of his previous big blocks. I don't recall why, but he did not keep that car very long.

72 Charger, 72 New Yorker 440
CH4B intake, 600 Holley 1850
Electronic dist with vacuum advance
Stock untouched bottom end with windage tray. 2.14 /1.81 new valve job pocket ported. Hooker headers
Comp flat tappet with I think .450 Lift. Maybe could find the card
TKO 5spd with the .82 OD 2.76 rear gear
Could easily pull more overdrive gear. .82 was a mistake. Pulled the original 3.23 and installed the 2.76
Steady highway gets 18mpg

Stock '72 440, TQ, vac advance, 3.23's in a '70 E-body gave solid 16+ in mostly highway cruises keeping it under 70.

i kind of figured the smiles per gallon were the measuring system for cost.

If mileage from a 440 is your primary concern, you will have to buy some KB quench pad pistons for open chamber heads, or build it to zero deck with some dish pistons to run withclose chamber heads.

There is some good info on the site about using the KB pistons and the resultant jump in gas mileage.

Not dumb, just my particular sense of humor relating to gas mileage and a 440 cubic inch motor.
Didn't intend to get you off topic...

NO problem thought I was missing something, we good. For the post above what about the 70 6 pac piston with a 452 head vs the way down in cylinder 74 piston (8 to 1) I have the whole external balanced assembly I could use.

I don't know if any of my 440s - or 383s, for that matter - in stock or near-stock form did better or worse than 14 MPG average.
All except 2 B-bodies, with the 2 being C-bodies.
Not that I was concerned about MPG, really, so I don't recall checking only highway MPG on the BBs.
My SB cars did better, as much as 17-18 highway MPG when I checked.

72 D series 1 ton crew cab, 4:11 rear, 33" tall tires, 727 trans. When I first got it, single digit mileage all the time, everywhere. After a rebuild, it began averaging mid teens in the city, high teens towing a trailer with a car on it on the highway. One extended unloaded trip from Denver to Phoenix, it broke 20.

The rebuild was nothing too spectacular. Basic rebuild with a balance job and as close to blueprinted as I could get. Used KB quench pad pistons with open chamber heads and ended up with a bit over 11:1. Smallish camshaft that had a little more lift than stock. Heads had a bowl blend. Also used dry film lube on all bearings and piston skirts and thermal coatings on piston tops and head chambers and valve faces. Ebrock performer intake and carb. Spent a lot of time dialing in the ignition curve.

Required pump premium to stay out of detonation. It was a towing beast in the mountains of CO. I could pass cars going up the pass to Eisenhower tunnel while carrying a load. The trip to Phoenix was a steady enough drive to really gauge fuel consumption and speed. Did the best at 75-80 mph range despite taching up higher than I wanted. Unfortunately, the high compression that gave it so much power and efficiency at elevation in CO was its undoing once in Phoenix. Detonation was a constant problem and I hurt it while I was there. Later pulled it apart and found a cracked piston. Rebuilt it at a lower 10:1 ratio. Performance and mileage was down as a result, but it also would live on lower octane.

I wonder if methanol injection would have helped?

Wow, I guess my 340 really sucks.
Never got better than 12mpg and "jumped" to a best of 16-17 after I added 518 OD.
And you guys are getting 20 or more in B and C bodies, just amazing.

i forgot about the 73 4x4 yard truck i had.
it was an original 318 2bbl/727, 3.91 gear, 32" tires.
with that engine, the best was about 8mpg.
with that said, it had a big "basher bumper" on the front made of 3" pipe and 1/8" plate.
the stock bed was made of 1/8" plate as well, had a 2" oak plank floor, and a 3" pipe roll bar.
total weight was about 7000lb empty.
put a 440 in it out of a 1970 chrysler wagon that was in the yard, added an rv torque type cam, and a thermo-quad intake from a late 70's [78 maybe ?] newyorker, plus using a big block 727 case during the rebuild, and using the output shaft and tail shaft of the small block 727. this allowed the original transmission mount and drive shaft to the transfer case to be re-used, and just needing 1/2 x 3" wide plates as spacers with properly drilled holes to bolt to the modified 318 block mounts and the factory frame mounts.
just changing the engine went from about 8mpg to 14 plus a couple of points.
i chalk that up to the 440 not working as hard to pull the weight of the truck compared to the 318.
unfortunately, i had to sell that truck to use the money for the paperwork needed when i bought my stupid house.
on a bright note, however, the family that bought my truck still own it today. it has been used as a pulling truck, a mud truck, and a street truck in the time they have owned it, and it still retains the engine and transmission i installed so long ago, as well as the "basher bumper" and bed i built.

I had a 74 Dodge extended cab 1 ton, Camper Special, non-dual open 4:10 gear, rear drive with a 440 and a 727. It had a wood topper on the bed with the top even with the top of the cab. The truck spent most of its time towing an open wheel car trailer. The truck and trailer empty with full fuel tanks weighed 9800 lbs. I had a 66 gallon bus tank in the bed, and the truck had dual Mopar installed gas tanks, just over 100 gallons when everything was full. 8 mpg, always! Empty, loaded for bear, and even with no trailer. I think I got 9 once, I figured I didn't get the tank full. I put nearly 150K miles on the brute. Even with all the weight, and a car on the trailer, the truck had power. When the truck was pulling the 6 mile long 7% grade with a Chrysler 300F on the trailer and parts in the bed, gas mileage was the least of your concerns.

The best gas mileage I ever got out of a Dodge truck (before the 90s Dakota with OD) was with a 400 4v powered old power wagon that didn't have much of the 4x4 stuff remaining. That one was consistently in the 13 -14 mpg range. 360s always got the worst gas mileage (about 2mpg worse) than any other Mopar motor except that 440 truck, but I suspect the 440 truck would have been worse if it would have had a 360,

The best gas mileage i can remember hearing of back in the day was around14.+ MPG on the road, not around town
I bought a used 1969 CHP Polara in the summer of 1969 that had a blown up 440 police pursuit motor, I think it had spun a rod bearing and I later rebuilt it with turning the crank and a set of rings and bearings
I bought a wreck, totaled roll over, 1965 Sport Fury 2 that had 19,500 on the speedometer, it had a 383 two barrel motor in it to install in the Polara to use as a family car, the best mileage I can remember that car getting was around 14.5 driving from SO CA to central Utah 850 miles away.
I learned later my wife could get better fuel mileage driving anything we owned on long distance trips, more than 50 miles. We had a 26 Ft. Class a Ute Liner motor home that she could get 8.5 MPG on the same road and traffic conditions that I got 5.5 MPG
I would drive it from our home out to the first rest stop to wherever we were going in it and then she would drive it the rest of the way. She didn't like driving it in town
Ultimately the right foot controls the fuel mileage, heavy foot bad mileage, light gentle foot better mileage

No doubt it would have solved the problem and allowed me to keep the higher ratio. I didn't want to get into it because I arrived at a decision point to sell it and a two seat sports car for a newer crew cab truck. While I certainly do miss the cool factor of towing into an event with a vintage crew cab, I really love my new Ram which does everything the two previously owned cars did and does it better, in more comfort, with fewer issues. Although mileage typically isn't significantly better than it was with my old truck combo.


A great tool for improving mileage is to use a vacuum gauge. Try to keep the vacuum reading high and your mileage will follow.

the old "mileage minder" gauge with the green, yellow, and red sections on the face.

I average between 8 and 10 mpg with this stunning example of automotive efficiency.

I wonder how the fuel efficiency of a 440 V8 with EFI would compare to a modern effort like Ford’s 7.3 V8

That Dyno test comparison would probably never get funded today.

I do see a surprising number of shipping containers on open trailers being hauled on the interstates by 3500 size pickups.

I guess this is because of a shortage of “fixtures” that 18 wheelers almost exclusively used to deliver shipping containers “the last miles” to customers.

With today’s abnormally high diesel prices I have wondered if gasoline 3500 pickups could deliver shipping containers at a lower cost per mile than a modern diesel that also requires buying DEF..

Swap in a big cubic inch 440 stroker with EFI running a 20 to 1 AFR into a 1994 Ram Dually and see?

What transmission (or camshaft) would be another challenge....

I know I asked about 440 millage but that’s in a 79 truck. What I would do on the newer trucks is get a 392 engine like what's in my 15 SRT, to replace a 5.7. I’m getting 25 mpg in the car and weight should be close between the two, has anyone done this? Not talking about the ‘truck’ 392 dog.

It would be pointless. Today's engine architecture is vastly superior to the 50s era technology used to build the big wedge.

Compare a 5.7 hemi and a 318/340/360. The new stuff makes much more power and gets far better economy.

While not specifically 440 based, there have been numerous carb vs efi tests on performance engines over the years. The vast majority of them have shown that power and efficiency between the two is actually very narrow, if you spend the time to optimize all the circuits of the carb. Carbs actually make just a bit more power while efi has slightly better BSFC numbers. Of course, at the OEM level where a fleet number matters, even a .5% increase in mileage has big implications over the selling of a million + cars. Often the failing point with a number of enthusiasts is that they only work on the carb until it is "good enough" for power production and never dial it in to the Nth degree for high vacuum, low throttle angle, cruising at a steady speed. I also seem to recall reading that the biggest advantage of the efi is at start up and cold temp operation where it avoids fuel washdown of the cylinder walls and the resulting dilution of the oil that carbs have a very hard time achieving.

Whether a gas big block could become as economically equivalent to a diesel for hauling, perhaps over a short time and perhaps only in 3500/4500 chassis and smaller. I doubt the gas engine will have the longevity to offset the diesel's capability so periodic rebuilds would tilt the longer term savings back to the diesel. I also suspect that in truly heavy duty applications, like over the road trucking pulling 53', fully loaded trailers, the gas engine would need to displace so much, that its fuel consumption would sharply fall against the diesel. There is a reason why OEMs haven't tried this yet and that because even at higher prices, the diesel engine is still an efficient way to perform this work.



Hmmm, I bet there is a bigger gap in weight between these than you think. SRTs are around what 4500-4800#? My '09 Ram crew cab short box is 6000#. I'm willing to bet a 3500 is easily over 7000# I'd also venture a guess that the 25 mpg you see is on cylinder deactivation while cruising on level ground. My Ram will hit 20 in those same situations, unless I'm hauling. While towing a load, its rare that my truck ever hits deactivation mode. Pulling my 20' boat, my mileage drops to low teens. I haven't towed any of my cars for any extended period to compare, but they outweigh my boat by around 1000-1300#, so I'm willing to bet my truck mileage would drop towing them for hours at a time.

The 72 Imperial with its CA smog motor, 3.23 gears, and 29" tires knocked down 15 mpg a few times. I doubt the 541 will do that.

My old hot rod did fairly well. 65 Belvedere twin turbo efi 440 with 833 OD, 3.23 gears, and 29" tire got 19 mpg running 65-70.

Back in 2001 we did one of the prototype TKO transmission swaps in a 70 440+6 RoadRunner with 3.54 gears. On the drive from Dallas to the Nats he got 17 mpg at 65 mph and 18 mpg at 75 mph. We think the engine was being lugged down too much at the lower speed.

The official DaimlerChrysler press release said the 2004 5.7 Hemi was
“6% more fuel efficient than the Magnum 5.9V8”

They did not explain whether that was
6% more fuel efficient at peak torque (traditional SAE comparison)
or 6% more fuel efficient in the (somewhat crazy) EPA dyno fuel economy test.

That odd year I believe you could get either engine in a Ram, but auto trans differed.

With the roughly 55 year difference
I would guess 0.5% per year improvement
between a 440 V8 and a 7.3 V8
but the super strict NOx emissions the 7.3 has to meet is a “heavy burden”
and the ethanol in today’s gasoline has to be factored in.

I bet with 4.10+ gears and the same cruise RPM that was used @ 75 would net some good MPG gains