3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

Vehicle efficiency upgrades: 30+ MPG in 2.5ton commercial truck

Step 3Disconnecting extra engine loads: fan, pump, alternator, a/c

disconnecting extra engine loads: fan, pump, alternator, a/c
«
  • 101_1651.JPG
  • 100_2397.JPG
  • 100_2392.JPG
  • 101_1653.JPG
  • 101_1449.JPG
  • 101_1447.JPG
  • 101_1595.JPG
  • 101_1829.JPG
  • 101_1832.JPG
  • 101_1442.JPG
  • 101_1422.JPG
  • l_07f48e10c9ad478ab96c7ac63c288872.jpg
  • l_97ca6d69d9254ca2be9c87bd40a8232e.jpg
  • l_2d73694d6eeb4ffdb307ae3fba847723.jpg
  • last photo ←
»
A surprisingly large amount of the money you put into the gas tank never makes it to the wheels.  I read somewhere that only about 1% of the energy in gas actually goes to moving the driver.  Roughly 1/2 of that energy just goes into turning the engine.  The law of thermodynamics won't let you recover much of that waste, but you can reduce the parasitic loads between the engine and the wheels.  Every belt driven accessory gets it's power from the gas in the tank, so reducing the accessories will noticeably improve mileage.

-I replaced the stock engine driven hydraulic clutch cooling fan with an electric one.
The fan adds to the battery load, but it is much lighter, so it does not require as much force to turn. Also, it is only needed when driving very slow or idling, as otherwise the movement of the vehicle provides air flow. The stock fan turned at all times, no matter what temperature the engine was at.
This also helps the engine run warmer, which makes it more efficient in cold weather.

-I replaced the belt driven mechanical vacuum pump with an electric one.
This step is only relevant to diesel engines, as gas engines generate vacuum directly (no need for a pump) - unless you coast with the engine off. With an electric vacuum pump the brakes work the same whether the engine is on or off.

-I removed the power steering pump and replaced the steering gear with one meant for manual steering. Even in a truck this size, the only time it is at all difficult is when turning the wheels at a complete standstill. Other than parking in tight quarters, power steering is totally pointless.

All electric power in a car is generated by the alternator, which is powered by the engine, so any reduction in electric draw ultimately reduces drain on the engine.

NOTE: If anyone is inspired to do a similar project (with any vehicle), do not just disconnect the alternator from the battery w/o disconnecting the smaller wires. It will continue to produce current, but since that charge has nowhere to go, the alternator will self-destruct.
Also, diesel trucks tend to have very large batteries. Mine has two. This gives me a lot of reserve power to tap into without draining them too much. With an ordinary car battery you will damage it by cycling it too deeply. Once it finally dies, replace it with a deep-cycle (RV or marine) type battery and you'll be fine.

-The orange (on an '83 F-250) wire running from the external voltage regulator to the alternator controls whether the alternator is charging or idle. If you open the circuit the alternator stops charging. Even though it is still being turned, there is no resistance, it just freewheels. At first I just disconnected the wire, and later I installed a switch so that if the battery ever does run too low, I could charge it with the engine just by flipping the switch.
I used it so little that I eventually just removed the alternator altogether, thereby eliminating the belt and a little bit extra weight.

Since the battery is no longer being charged by the engine, I needed to reduce the electric load as much as possible so the battery will last.
I installed a 15watt solar panel to charge the battery. It sits on the passenger side of the dash board while driving, but when I stop I place it on the roof to get more direct sunlight.  If I drive for several hours (with my 400W stereo system on), the solar panel can fully recharge the batteries in about 2-3 days of full sun.  If I need to drive again sooner than that, I also have an onboard 120v AC charger which plugs into a standard wall outlet, much like a plug-in hybrid.

-I ordered extra bright LED bulbs (from superbrightleds.com) for the taillights and tun signals. They are brighter than stock but draw less power. The original parking/brake/signal lights together use more power than the headlights, at 63 watts (parking) to 177 watts (brake) stock. The LEDs total 5.5 to 20 watts.

-The dash lights alone used 15 watts. When I took apart the dash and instrument gauge, I discovered that the original system deliberately blocked and wasted the majority of light the bulbs put out by covering them with a slightly translucent cover, and then shielding the gauges on 3 sides. Which explained why the dash was always so dim. I broke off the filters, cut away the plastic shielding, and instead built reflectors (out of metal tape) to direct the tiny amount of light of my new bulbs on to the gauges. The result is far brighter than it was, and is all red which is easier on night vision, and uses less than 1 watt for all 8 bulbs together (plus it looks really cool).

-I added a voltmeter so I can monitor the batteries.

-I had been thinking about making a buzzer to remind me if I left the lights on, but then it occurred to me that there is really no situation where I need the lights on and don't have the keys, so while I had the dash apart I also rewired the headlights (and aux driving lights which I also just installed) so that they go off when the key is turned off - now I can't possibly accidentally leave them on and drain the battery.

-If I had air conditioning, I would have removed it.  But I didn't to begin with.  You can stay cooler with beaded seat covers over thin white fabric and heat-blocking lightly-tinted window film, available from any auto parts or hardware store for around $15.  Last summer I painted my roof silver to reflect the sun light and keep it out of the cab.  I also have a small 12volt fan on the dashboard.
If you absolutely can't stand the heat, even with the roof painted silver, heat blocking window tint, beaded seat covers, and a smll fan blowing, you can always roll down the windows just a crack to provide additional ventilation.  Opening them just slightly still hurts your aerodynamics less than rolling them down all the way.
It also helps to wear no more clothing than is legally necessary.
« Previous StepDownload PDFView All StepsNext Step »
19 comments
Jan 27, 2012. 8:57 AMearthwindwater says:
Thank you for explaining the Alt delete!
Apr 7, 2010. 9:38 AMjustinRgray says:
I like  your approach to saving the environment: make you car or truck so annoying to drive at any given point you will just give up and ride a bike.
   LOL
Nov 4, 2010. 1:19 PMmorbidmx says:
your way of seeing life and help actively to the conservation of our planet is commendable. the search for maximum efficiency of resources, is so foreign to today's lifestyle, which to most will seem ridiculous changes you made to your truck.

However, it is justified and is nice to see the commitment that you have acquired through the use of your resources. Not only have you changed your vehicle, your habits and customs also

will try to do the same with my truck
May 20, 2010. 11:26 PMnerys says:
I agree. Makes it a lot more fun. Game Like more competitive. Even entertaining.

Got pulled over tonight (a light was out) combined with me doing 45mph in a 50mph I guess I passed their "itch" thresh hold and the out light gave them the probable cause they needed to pull me over.

No problem all paperwork in order etc.. but on mentioning I was driving slower to save gas (there was no one behind me) he said got other things to worry about than a little gas.

I came back with $1100 in gas. He looked at me and said what? I said slowing down 5mph saves me $1100 in gas a year.

Just look at me oddly with shock :-) I said I drive 40,000 miles a year. a 3 mpg increase over 40,000 miles is about $1100 a year. (actually $1066 but $1100 was close enough)

He said. Oh and went back to check my papers.

I bet he checks his mileage this week :-)
Jul 4, 2010. 8:21 AMJoenavy85 says:
That's what i do, i'll drive home from my friends house and try to get my average MPG as high as i can. it's about 25 miles and is a mix of city and highway driving, but unfortunately the highway portion doesn't have many semi's but it does have the occasional stoplight which gives me an excuse to coast. I coast in neutral up to every stoplight and i stay in neutral until the light turn green (no different than having a stick shift and waiting to put it into first). on downhill sections i "pulse and glide" to the exit (about 1.5 miles) and coast up the off ramp to the light in neutral. Last night i averaged 25.2 MPG from her driveway to mine, and that was with having to completely stop at 6 stoplights, one of which was on the highway.
May 21, 2010. 9:19 AMnerys says:
Oh heack yes :-) same name :-)
Feb 11, 2010. 7:14 AMJohnMichael says:
While a diesel engine may be able to run off the battery, that does not work well in gasoline engines.  Gasoline engines need enough power for the plugs to spark and without the alternator the battery would be drained.  In most cars the battery is only used to start the engine.  Once started it runs off the alternator not the battery.
If you are going to run your diesel off the battery you might consider a deep cycle battery such as the ones used for electric powered boats.  They are designed to run for longer periods before being recharged.
Nov 29, 2009. 7:24 PMImageMaker says:
I was told (in connection with a failed safety inspection on my own 1990 Aerostar) that, at least in North Carolina (though likely the case in other states with safety inspection, as opposed to emission testing only) a vehicle originally sold with power steering must have the power steering in place and functioning to pass safety (which includes not having low fluid due to a leak, which is how I got tagged).  Thus your conversion from power to manual steering would be illegal here, though it might well be legal in other states.  Also worth noting that in a vehicle with rack and pinion steering, like my Aerostar, removing the power steering is a Very Bad Idea (rack and pinion feeds back too strongly to drive without power assist, except in very small, light vehicles).
Jul 25, 2009. 6:42 AMPeaceByJesus says:
I have often wondered what the MPG would be on a truck like yours, using applicable modifications, when using a diesel-electric hybrid. Perhaps it would not be worth the crossover expense for you, but I read that the military made a Dodge Ram pick up into a DE hybrid. , Honda was trying out a diesel-electric tractor, and Mack Trucks has one, while Philly planned to buy Diesel-Electric hybrid buses.

For cars, I read that Volkswagen made a prototype diesel-electric hybrid car that achieved 2 L/100 km (140 mpg-imp; 120 mpg-US) fuel economy, and another that gets 239 mpg. But as trucks have so much space, what not SUV's etc. Much developmental news on this here: http://www.journeytoforever.org/biodiesel_future.html Battery tech is also key, and may those "super capacitors" have potential.
Apr 9, 2009. 8:24 AMbikerdude says:
Good Instructable. it shows that gains don't cost a lot. In step 3, did you remove the alternator from the engine ? If you are not using it, it add some resistance albeit small, on the engine. Rather than charging it at home, why not install a solar car/RV battery charger ?
Apr 19, 2009. 6:22 PMSpeedKnight says:
In the relatively early days of NASCAR, a guy named Smokey Yunick tried something similar to this. What he did was mount the alternator on the front of the car with a propellor attached where drive pulley would attach. It worked perfectly, and there were never any issues as would arise with not having an alternator at all. As an aside... Smokey was fined by NASCAR for cheating. As one would expect, he got better gas mileage than everyone else with this set up. NASCAR wouldn't allow it. Eventually, Smokey gave up on NASCAR and just quit.
Apr 24, 2009. 1:46 PMdnarby says:
I dream of fabricating a pulse detonation engine to fire into a huge turbocharger directly mounted to the drive axle.

Check out a search for turbonique http://www.tfd.com/_/search/google.aspx?q=turbonique ...And that's not being driven by a PDE, which uses a much more efficient burn method.

...Now imagine that you AREN'T trying to go 230 MPH, just using the PDE/Turbo to operate your car normally.

I bet we'd easily get >100MPG in a full size car.

Can't wait until we dump the engineering anachronism that is the petroleum powered piston engine.
Apr 10, 2009. 11:56 AMLarek says:
This is a diesel engine so you're ok, but I would not recommend this "with any vehicle". Gas engine needs an electrical spark, where a diesel does not. The spark does consume a noticeable amount of power over a relative short drive. And will need more than normal battery to supply it.
Apr 16, 2009. 10:14 AMchrwei says:
back when I was delivering pizza my alternator belt broke, I have no idea how long it was like that since the car's indicators were broken. I only noticed because after turning the headlights on for about 30 minutes the radio got all weird and the headlights dimmed. I was able to finish the delivery and get to parts store (about 7 miles) for a new belt and still had enough juice to start the little 4-banger again. with a deep cycle battery and not doing at night, running without the alternator is feasible in small cars. If I were to do this, I'd want an amp meter as well as a volt meter though, so I can read how much power I'm drawing and judge how much time I have left.
Apr 8, 2009. 4:33 PMSwishercutter says:
I love the speedo needle...someone after my own heart.

Pro

Get More Out of Instructables

Already have an Account?

close

All Steps Viewing
View all steps of an Instructable on the same page when you're a Pro Member.

Upgrade to Pro today!
46
Followers
7
Author:JacobAziza
I am an ordinary guy. Except that I live in an RV, drive a 250cc motorcycle, have a truck that runs on bio-diesel, am vegetarian, and have had almost 30 jobs in 10 years, including armored truck drive...
more »