Fuel Economy is Too Good ...

[Admiral]

So, I took my car on a nice drive last Saturday. Before heading out I went to the gas station a mile from my house and filled the fuel tank. After that, I took my trip, which involved a good mixture of driving, it was mostly country two-lane travel but there was also a fair bit of stop-and-go and some highway motoring.

When I got back to my neighborhood I'd driven 92.2 miles (according to the odometer, which I think is conservative according to GPS). I went back to the gas station and filled the tank again, which required 4.317 gallons of 87 octane. According to my math, which isn't very good, I averaged better than 21 miles per gallon. HOW IS THIS POSSIBLE? I mean, I'm not complaining, but something doesn't seem right. It shouldn't be that high, should it? And I'm not afraid to rev it up or cruise at 65 miles an hour.

My car's engine is basically stock aside from dual exhaust, an 80-thou overbore and 12-volt electrics. It's got a 3.78 rear-end and NO overdrive.

[35fordtn]

My 35 with a 3.54 rear gets around 22 highway. It makes me laugh everytime, as my 1996 F-150 gets 8

[Floyd]

The fuel mileage from "back in the day" according to the service bulletins says 20 to 22 MPG is correct. What this tells me is your car and engine is set up correctly as to timing, carb, tire pressure etc. Also it probably does not run hot.
Congratulations, a lot of these cars are reported at 12 to 13 mpg. However they usually have typical problems of over rich mixture, late timing and other things that are wrong.
If the 4.317 gallons is correct to fill the tank back to exactly where it was when you started, you are good to go!
Just an opinion

[uncle max]

Rascally flathead, dual carbs, Mitchell overdrive; I get 22 too.
Everyone hates me.

[Lawson Cox]

Originally Posted by 35fordtn

My 35 with a 3.54 rear gets around 22 highway. It makes me laugh everytime, as my 1996 F-150 gets 8

And you're BITCHING???

[JSeery]

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Your numbers may be dead on, but remember that you really can't calculate gas mileage with one sample (and a fairly small one at that). It takes at least several fillups and then average the results. You should be able to check your speedometer by using the milemarkers along the highway. Again, not just driving one mile, drive several miles and see how the odometer compares to the milemarkers.

[Admiral]

Originally Posted by Floyd

The fuel mileage from "back in the day" according to the service bulletins says 20 to 22 MPG is correct. What this tells me is your car and engine is set up correctly as to timing, carb, tire pressure etc. Also it probably does not run hot.
Congratulations, a lot of these cars are reported at 12 to 13 mpg. However they usually have typical problems of over rich mixture, late timing and other things that are wrong.
If the 4.317 gallons is correct to fill the tank back to exactly where it was when you started, you are good to go!
Just an opinion

Yeah, I think it's dialed pretty well. She starts instantly, idles smoothly and pulls strongly. I can't imagine how well it would do with overdrive.

I was talking to an EFV8 club member a couple years ago at Hershey. He has a 1950 or '51 sedan with the V8 and overdrive. He said he averaged like 29.5 miles per gallon on a drive of around 500 miles getting there. I was floored when he told me that but now I believe him.

[Bruce Lancaster]

Here's part of an old post with some of the Ford standards for level road/steady speed driving:
On another project, I located some economy standards in the Ford "Performance Services" section of the manual, along with accel and speed standards. Note that numbers are not real world, they are for short tests at steady speed/level road measured with the normal Zenith 1/10 gallon mileage tester. They only have specs with commonest axle ratios, but the different cars give a good spread of those.

1935-6 85HP, 4.11 37.1 @ 20, 22.8@ 40, 18.7 @60
1937-40 85HP, 3.78, shows 31.7, 26.2, 20.9...reasonable comparison for the above. No 85's were commonly sold with 3.54, but there are 239 numbers for the 1940 Merc with 3.54: 29.3 @20, 26.3 @40, 21.9 @ 60, numbers run 1--3MPG better than '39 Merc with 3.78.

These, as noted, are pure steady state tests done just to see if a customer complaint was a car or a driver problem, but they give some indicators. You can see the reason for the national 40MPH top speed during WWII!
With a heavyish car and 221, you might well like 4.11 or 3.78 with the overdrive. I too suspect gearing would be toodamnhigh with 3.54 and OD.
Tests listed in the bulletin do seem to confirm that bigger engine with higher gear is better on fuel than smaller with the requisite lower gearing.

Note that these were Ford's standards and expectations based on a simple test (Zenith tester) using dealer equipment; this means if someone complained about mileage the dealer was to perform the specified test...if car did not meet mileage standard, it need work. If it met spec...the complaining owner needed driving lessons.

[JT FORD]

Take that 29 mpg with a grain of salt! I've had 6 of this 49 -53's and they don't get that good...

[cmbrucew]

In the late 50's I would fill up the oil, then check the gas.
Never checked gas miles per gallon.
Bruce

[Admiral]

Originally Posted by JT FORD

Take that 29 mpg with a grain of salt! I've had 6 of this 49 -53's and they don't get that good...

Maybe his drive was 500 miles downhill to Hershey.

[34fordy]

Originally Posted by JT FORD

Take that 29 mpg with a grain of salt! I've had 6 of this 49 -53's and they don't get that good...

You are probably right but I bet the fish they catch are pretttttty BIG!!!

[Kahuna]

My car will exceed 22 MPG. This is a flathead of 290 cubes, Potvin 425, dual 4 bbl carbs and a bunch of other mods.
I run a 4.11:1 axle and an overdrive.
Flatheads are cool

[A bones]

Originally Posted by 34fordy

You are probably right but I bet the fish they catch are pretttttty BIG!!!

A line I heard once from a C~W SONG

'Our stories aren't always true, but we sure do remember them well!'

[JWL]

My Flathead powered cars will NOT exceed 22 MPG with me driving them.

[Bored&Stroked]

It seems I'm not capable of achieving 22 MPG in anything that I drive . . . even a late model four cylinder Subaru. Of course, it was making 310 HP on the turbo!

[RalphG]

I've never driven the 52Merc more than a few miles at a time so can't comment just how thirsty it is for gas. Fuel economy was a selling point for Mercury back when they were new. Usually with the standard and overdrive transmission.

[gajeepguy]

Back in the day, our local Standard Oil Dealer sponsored a Saturday "economy run" and it was well attended by the locals. First prize was a trophy plus free oil changes and eire rotation by the station. I don't remember the numbers (I only remember in was in the 30's ) but a 1953 Ford with overdrive was the winner for many years. Nobody else even came close........ -RG

[petehoovie]

If you're addicted to and can afford this hobby, it would seem that 'fuel economy' is not a priority....

[JSeery]

Originally Posted by petehoovie

If you're addicted to and can afford this hobby, it would seem that 'fuel economy' is not a priority....

I have to agree with that one!