Hey guys im looking at doing some weight reduction on my 1971 f250. Im doing this to get a little bit better gas milage. I read that for every 100 lbs you get an extra 2%. With that in mind i have stripped about 200 lbs of stuff. Ive lost the huge rear bumper (for now) all badges, the cracked dash pad, un needed speakers, original radio, extra battery and battery tray, and a few other miscellaneous goods. But ive been looking and i need to loose the extra gas tanks. I dont need them any more so they are extra weight. I have dual saddle tanks on the left and right side between the bed and frame. How are they removed? Ive looked and i dont see any easy ways to remove them. Any body done this before?

Thanks guys

 

I'm not sure how much more you have to gain there. These trucks are already pretty light, especially compared to an 80s-90s model.
Your best gains would be in controlling airflow, especially under the truck and around the mirrors. If you replaced your mirrors with the more aerodynamic ones used on later trucks you'll probably get a noticeable difference. This is the style I am talking about:

I am going to be testing out a front air dam next weekend, it should be good for a couple MPG as well.

 

Unless you're on the highway for most of your miles the aero improvements, as miniscule as they would be, will not have any noticeable effect on MPG. The frontal area on these things is the killer, along with the boxy shape.

The weight savings will help for start/stop driving...200# is a huge savings, well done!

Now completely disassemble the chassis and acid dip the sheetmetal and frame, put it all back together with titanium bolts, and use a single thin coat of paint on the body for another 150# or so reduction!

 

Put your badges back on.. If you want it lighter, put a 9" and 5 lug the front, aluminum intake, aluminum wheels

 

Weight reduction...
Fiberglass body parts
Lexan rear window and doors
Swiss cheesed non-structural panels
Wireframed radiator core support
Wireframed inner fenders
Lose the hood hinges
Lose the tail gate
Lightweight seats and brackets
Lose the carpet
Lightweight front bumper

Aero...
Seal up all front end body gaps. Ever notice the grill opening is much larger than the radiator opening?
Install an air dam... the undercarriage is a mess of turbulence.
Install and underbody tray and side skirts.
Shave the body.. door handles, mirrors, wipers, rain gutters, emblems. Make it slick.

Mechanical...
Decrease the rolling resistance with high aspect ratio tires
Electronic fuel injection
Cold air induction
Headers and dual exhaust
Synthetic engine oil, tranny lube, and axle gear oil
Overdrive transmission
Aluminum or carbon fiber driveshaft

... and drive like a nun.

 

... and drive like a nun.

same as the chevy truck drivers on the Phoenix freeways....... <!-- / message -->

 

hmm 100lbs = 2% guess I am dieting DR said i could lose 100lbs

 

Hmmm where to start. Well the first week and a half i was averaging 6.5 mpg +/- After spending about $100 on gas for that time i decides to completely re think my driving. With me "driving like a nun" i brought it up to 8 around town. Thats a start... What are some easy, cost effective ways to improve aerodynamics and still be able to use it as a truck? This summer i am going to trim the rain gutter, door handles, and weld in the body seams to decrease drag as much as possible.
For the light weight performance parts those will have to wait. Im on a very tight budget between gas and finding the money for a new dirtbike. So the aluminum intake, efi and other things like that are on hold.

About 5 lugs up front, the truck is a 3/4 ton and id rather have 8 lugs all the way around. Summer come this truck'll have a camper on it so i cant give up any leafs either.

Mirrors. I do like the mirrors on me and my dads '97 f-250 (basically the same as the picture) but i love the big ole semi mirrors i have on the truck now. Not a single blind spot.

Im checking my gas milage again tomorrow or sunday so i will get back to yall.

And just so ya know this is stop and go around town. No highway as of now.

 

Sister LilSmokey!

Cost effective aero? Lose some easy weight like the tailgate.. costs nothing but a few minutes of your time.

Second, do a test using tape! Not duct tape which leaves a sticky residue. Instead, get some racing tape from the roundy-round parts houses like cmwraceparts.com or speedwaymotors.com and tape up the body seams, grill, and grill opening on the front end. Leave a "window" the same width as the radiator. Now install a piece of cardboard to get rid of the hood's reversed lip on the leading edge. Then to at least a 50-mile, highway test loop to determine what kind of MPG it can generate.

Third, head to the JY and locate the front air dam or duckbill off a newish Econoline. Blocking the oncoming air from hitting the suspension and crossmembers will help.

After each mod or few mods, repeat the same test loop to determine the marginal gain. Try to replicate the test under same conditions - vehicle speed, rolled up windows, vehicle traffic, temperature, and wind conditions. I find that early Saturday and Sunday mornings are good times.

 

Third, head to the JY and locate the front air dam or duckbill off a newish Econoline. Blocking the oncoming air from hitting the suspension and crossmembers will help.

Not trying to steal thread but anybody got a pic of a truck with an air dam on it. Sounds like an interesting/cheap upgrade.

 

Sure. There was a build thread a couple of years ago from which I saved the pics below. I recall the owner found the piece on the side of the road so he didn't know what it came from.

For the life of me, I cannot find the thread. Maybe someone bookmarked it so please chime in.

 

Not bad, thanks for the pics! I think as suggested econoline would be the place to start looking. Looks like I will be bring a tape measure with me next time I go to the junkyard.

 

I've not heard anything under the hood too twink some.
I've changer over to an late 79-80's truck clutch fan.

Just adding dual exh. helps..An if you have the bucks do a complete custom setup that flows out better helps save gas.

Upgrade too a Better Ignition system helps save gas.

Check carb jetting it maybe wasting gas. Read the spark plugs color and start putting in 2-3 sides smaller.
Do a poor mans cold air intake tube from alum clothes dryer exh tube.

At a K&N filter or do the poor-mans flip air filer cover top.= more air

For Hwy driving don't go over 55 mph, keep tires aired up -45-55 depending on tires ratings & max PSI with loads..
Now P/S A/C All take away power that adds to your lost fuel mpg.

With a can over camper use the cab to camper inflated donut helps save gas.
Plus don't fill up your water tank until you get to the camp grounds.
Plus i've found when you have a camper you load it full of stuff that you can think of that you could use. But it never gets used just hauled around adding wt. to your camper load.. Just Food for thought my 2cents..
orich
my 2cents orich

 

Oh, how things have changed in 10 years! Do you seriously want to lighten the old bump side? Yesterday, in issue 20 (Spring 2023) of F-100 Builder's Guide, there may be an answer to all those questions!

Brother's Composites has built composite body parts for the Ford Bumpside. I'm sure this will lighten up the old truck and your bank account, but they did a great job!

 

I wish you the best of luck, with your quest for better mileage, but I doubt your going to gain a lot regardless of what you do.
An older F250 is a pretty poor candidate, for this in the first place, as they are heavier than their 1/2 ton brothers.
The F-250 trucks have thicker, heaver frames, springs, heavier wheels, and tires, heavier rear axles with more drag, lower gear ratios, and the shape of these trucks is much like a brick.
Back about 40 years ago, I was in Auto body school, 45 miles from where I lived, and I made a lot of trips, back and forth. Being poor, mileage was important to me, and I tried a few things to help it out. Below are my results.
My 71 F100 had a fresh but stock, 1968 302 car engine with a 2 barrel holley carb, electronic ignition, and dual exhaust. I ran, 350 final gears, and a 4 speed compound low trans, and stock wheels and tires. I did not run a tail gate, as I did not have one at the time, and with the speed at 55- 60 MPH.
I would get about 16 - 17 MPG, and most of the time more towards 16, than 17. This was the high water mark, as far as mileage went.
When I swapped carbs, got a little better mileage with the small 2 barrel holley, over the motor craft, carb, and electronic ignition helped a little.
When I put a tail gate on, I lost about 1 MPG, and when I got tired of shifting all the time, and put a small block C-6 in it, I lost another MPG.
I changed to 300 final gears and picked up a little, but not much. I was a pretty reliable truck, that made a pretty dependable 15 MPG, on average, with most of this on the highway.
Your biggest improvement will come from a well maintained, carburetor, freshly tuned engine, and possible electronic ignition would help a little bit.
Also after market aluminum wheels, and lighter duty tires, might help a little bit.
With all of these things, I would not expect an F250, that most likely has and FE engine in it, to get much better and 11, or 12 MPG, on the highway, and 8-9 in town.
Best regards,
Brad