The Stovebolt Site Forums The Shop Area General Truck Talk mpg??

hey fellas I was wondering if any of you might have a idea of what mpg a 1952 panel 3100 might get with a 235 engine , 3 on the tree and 3.55 rear gears?

What rolling diameter tires?
Standard/original carburetor?
Brakes adjusted properly
Front-end alignment set up properly

All those factors are "in the mix".

What average speed?
Level roads or hilly roads?

What was you former gas mileage?

12-18 mpg, depending on roads and you maximum/average RPM?

My 1953 panel with 3.55 gears and a 261 gets 22 miles per gallon on a long trip. Transmission is SM420, same high gear as a 3 speed and tires are maybe a hair under 30" tall.

What MPH on that long trip?

Thanks fellas! that gives me a rough idea , and is what I was looking for. To answer your questions.. I am running 6.50 x 16 tires. as far as I know it is a stock carb. and the steering seems to be in good shape. also think the brakes are as they should be too. so if I can get 12-22 mpg then it might be worth changing the ring and pinion and not sell the truck just yet... also does keeping the torque tube system help the truck keep its value or would it be more valuable with an upgrade to an open system?

Wendell, I got the 3.55 setup, had the machine shop install it for me, very happy with it. I kept the torque tube. Top speed is 87 mph as per my GPS, but don't cruise there.

"I am running 6.50 x 16 tires."

"if I can get 12-22 mpg then it might be worth changing the ring and pinion and not sell the truck just yet
"... also does keeping the torque tube system help the truck keep its value or would it be more valuable with an upgrade to an open system?"

To compare MPG, you need to estimate RPMs and then estimate resulting MPG (gas mileage).
- how much level-MPH driving vs start-stop/speed-up-slow-down driving affects MPG?
- what average speed?
- is your alignment good (all parts adjusted and lubricated)?
- are front wheel bearings good, and adjusted?
- is your steering-gear adjusted?
- is your air pressure set to minimize wandering (higher pressure) and minimize hard-steer (lower pressure)?

My 54 3100 with 3.55 R&P and 31.5" (or, a little less) rolling-diameter radial tires approximately gets the following MPG:

Ring Gear and Pinion Ratio (3.08, 3.55, etc.) = 3.55
Tire Height (24.5, 26, 27.5, etc.) = 31.5" (truck radial tires)
MPH = 55
Transmission Final Gear Ratio = 1.00
Calculated Engine RPM = 2083 (your RPM would be about 5% higher RPM at same speeds)
Estimated MPG = 18-20 MPG

At different MPH (minimal start/stop driving):
MPH = 55, 18-20 MPG (2083 RPM)
MPH = 60, 14-18 MPG (2272 RPM)
MPH = 65, 12-14 MPG (2461 RPM)
These are crude estimates and 10-20% off.

I used the RPM calculator at the bottom of this page.

I have pushed-it (a 261) to a little over 90 MPH.
65-70 MPH is my highest cruising speed, with noticeably lower MPG.
The decreased MPG is not only a result of RPMs, it is a result of wind-resistance (the awful "aerodynamics" of a Stovebolt).

Keeping the torque-tube (with 3.55 rear) is better than a chop-job front/rear suspension and poorly-implemented different drive-train & braking system. If the changes are done well/correctly, they might enhance value.

If you change drivetrain, suspension, and brakes (and engine parts) with non-major-manufacturer-style/design parts, the next owner would probably have a harder time finding replacement/repair parts, unless they are all stock major-manufacturer parts.

mostly around 65,

3.55 R&P
1:1 high gear
30" tires
65 mph
RPMs = 2584

22 miles per gallon on a long trip

Very nice

Well fellas again I thank you. you fellas have given me what I was looking for, a general idea of fuel milage. I am finding that the swap could cost me in the $1,200 range ... my other car ... a 2006 pt cruiser has got a bad wheel bearing. and if the pt cruiser was in good condition it might be worth $600.. tops!! so I have a dilemma ... I really don't want to put money into the pt cruiser , and it would take a fair amount of money to get the 52 panel up to speed.( ring and pinion swap) I really should not drive the cruiser at the moment , and I am glad I have the option of getting to work via the panel truck albeit slow ... for now... luckily I am a only a half hour from my work place. maybe 40 min. in my panel .. I am need to figure out what to do, and promptly.... gray areas are such a tough call....

Wendell, just so you know...our imperial gallons are 25% bigger than the US gallon. If I converted to the US gallon, I would get approx 18.3333 mpg.

18+ MP(US)G is pretty good

Dirty pool!
How many imperial gallons per kilometer there, Fast Eddie?
Carl

well ... I have decided to not sell my panel just yet.