The Stovebolt Site Forums The Shop Area General Truck Talk Miles Per Gallon ?

Finally got everything done on the 58 apache and was set for another road test. 55 year 235 engine ,55 belair overdrive transmission, 3.90 rear end, new radials, shocks, brakes, and 29 inch tires on the back. I hit the interstate for Birmingham just west of Atlanta. The trip was cut short because the road got so bad after crossing into Alabama with all the construction. Total trip was 95 miles round trip running 65 and 70 mph flat out the entire trip some hills but no flat land. Took 9.49 gallons to fill the tank back up. I got somewhere around 9.98 miles per gallon. Does this sound about right for the basic info provided. I don't think 18- 20 miles per gallons is being realistic driving at that speed.

0.73 overdrive?

2150 - 2300 RPM for 65-70 mph
(I used the calculator at the bottom )

If steady driving, 18-20mpg is believable.

How did you measure MPH and distance (GPS)?

My thought is that you should get better than 10 mpg. I get around 18-20 with mine. I have a 261, 3.55 diff, 30" tall tires and no overdrive.

13 MPG with the 4.10 rear and 235-85R-16 tires.

I used mapquest for the distance traveled one way and my speedometer for mph. My odometer was off by 3 miles with mapquest. Something must be really wrong.I used a half tank of gas for 95 miles

Yes, something is very wrong either with the math or the truck. I get around 15 mpg driving those speeds in my Suburban with 248 and the same OD.

On the road I'm getting 17 MPG with a '54 235, 4 speed, 3.55 rear and 16x7.00 tires. No OD.

In my 54 car with a 235, t-5 with the .82 overdrive( I think that is right, it's not the .73), and 205/75/15 tires, and 3.08 rear end gears I am getting at least 20 mpg running at 70-75 mph. I'm running Tom Langdons dual carb set up on a fenton intake with a set of Fenton headers. Something sounds wrong with only getting approx. 10mpg. Even when I still had the three speed with a tired motor I was getting 18-20 hammering it down the highway.

MPG claims of 20 or more @ 75 mph in my opinion is pure fiction. Like I say its only my opinion. I always take MPG claims with a grain of salt. Only my opinion!! and 2 cents worth


Weeds

Am I in trouble??


Weeds

Perhaps a 1954 car is a little sleeker (better aerodynamics) than a 1954 truck?

Hey Weeds, don't forget our gallons are 25% bigger than yours.

Canadian dirty pool!

Problem found a d Solved. The air adjustment screw at the base of the rochester b was all the way out. I ran the screw in all the way and backed out one and one half turns. Drove the truck 148 miles combined street and hwy. The fill up after driving was 7.39 gallons to top off the tank. That came to 20 miles a gallon. I am more than pleased with those results

Not in trouble with me Richard, I'm in your court.
I've had my '50, 3604 with it's original 216 for almost ten
years now and have 'logged' about 16,000 miles in the book.
Check the mileage at every fill up, a habit I formed when I
was flying to keep track of engine performance and condition.
I don't baby the old gal, my typical shift points
are at about 3,000 rpm and I do drive it in traffic and at
55-60 a lot of the time. 4.10 gear and 8.75R x 16.5 tires
which are somewhere over thirty inches tall.
Best I've ever gotten was 15, worst was about 10 and on the
average I run around 12 to 13 mpg.
Engine is rebuilt, Carter W-1 is rebuilt, distributor is
rebuilt engine runs fine, I've posted youtube of it on the
road recently, judge engine sound for yourself.

My new Silverado and I'll quote: "Chevrolet Silverado and
other full-size trucks, General Motors improves the fuel
efficiency of its mainstream 5.3-liter V-8 engine by
switching off four of the cylinders when they aren’t needed."
and it averages just under 16 mpg. Talked with other new truck
owners and Ford owners and 17 mpg is a good average for the
new truck. Most full sized cars struggle to get their mileage
in the low 20's.
Air drag is proportional to the square of the speed. So when
claims are made of high mileage at 75 and 80 mph it has to be
bunk unless you have run the design thru a wind tunnel.
Pushing a Chevy AD truck at that speed is like pushing a barn
door thru the wind, and that takes a lot of energy, which
translates to large fuel consumption.

So when I hear of high gas mileage on a 60 or 65 year old
vehicle, I say show me the numbers....all of them, over a long
period of fill ups.

Denny Graham
Sandwich, IL

Just be glad you're not figuring aircraft mileage which is figured in gallons per hour.

That is a good idea Denny. Now that I have a working speedometer and can keep mileage logs I am going to record mileage at fill ups to keep check on my performance over a year to see how it maintains.

I consistently get 17-20 mpg on a regular basis in my 1940 1-ton, although I rarely use more than 1/2 throttle it seem to enjoy cruising at 40-45 mph comfortably and I dont intend to push it, you have to remember that during that time period roads were narrow, many unpaved, and you cant really go that fast in town anyway, at lease in my situation, my driving simulates the speed of road conditions back when the truck was built.

Stock rebuilt 216, original heavy duty 4 speed trans, 4:11 rear, 7.50x17 splitrims (3/4 ton "special" KE, often listed at a 1-ton pickup)

In your situation with overdrive, I completely believe you attaining that MPG with those speeds using a 216/235.