Vehicle efficiency upgrades: 30+ MPG in 2.5ton commercial truck by JacobAziza
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[note:  new video has been added on step 1!]
[note 2: Most of what I write isn't relevant to Instructables.  My main blog is here: biodieselhauling.blogspot.com]

[note 3: Also save energy at home.  See my energy guide: instructables.com/id/Not-your-average-save-energy-advice-use-less-en/ ]

Go 50-100% farther on a tank of fuel.

Due to its size and weight this truck is considered a commercial vehicle and is exempt from even light-truck CAFE standards. Even so, with the modifications I have made, I am getting higher mileage than CAFE standards for 2009 cars.

I read an article in Mother Jones Magazine about Wayne Gerdes, mileage champion, and was inspired. I have read that people tend to get between 10 and 16mpg on average in the same truck I have. I was getting around 15. After the mods described here, on a recent tank I got 30.28mpg.

The best thing to do is to not drive at all. Ride a bike, take the train, carpool.
If you do drive, buy the absolute smallest car you can. If you only need a big vehicle occasionally, rent one.

I bicycle or use my 70mpg 250cc motorcycle for personal transport, but my truck still gets a lot of miles, so I wanted to make it as fuel efficient as possible.
I use this truck for work, moving up to 3 tons of soil or broken concrete, entire 1 bedroom apartments worth of belongings (including furniture) in a single trip, etc.
I also need something with enough power to move my 7500lb RV trailer (which is also my home - a very efficient way to live: I use as much electricity in a month as the average American home uses in one day)

Most of these steps could be done to any vehicle, increasing mileage from 50% to 100% or more.
 
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Step 1: The cheapest, and most important step

Modify driving habits

Single most significant difference, in any vehicle: "Adjust the nut behind the wheel"
(Drive more efficiently.)

Stay at (or below) the speed limit.
(Remember, you only save 7 seconds per mile going 75mph instead of 65mph, but stopping distance and wind resistance increase exponentially; twice as fast = 4 times the force)
(I have a much more in-depth look at speed at ecomodder.com/blog/slow)

Accelerate gently (Keep RPMs low whenever possible)

Never accelerate towards a stop light. (Every time you brake you are wasting momentum.  Remember this with the rhyme: "if you have to break, you made a mistake)

Never idle. A popular misconception is that it uses more gas to start than to idle. This was true of older (carbureted) engines. This is not true of modern (fuel injected) engines.

More advanced techniques include actually shutting off the engine and coasting as often as practical. (This can change the feel of the brakes and steering, see step 4)

(PLEASE READ the entire instructable and all the comments before commenting about how dangerous it is to coast.)

NOTE: many automatic transmissions can be damaged by coasting with the engine off.
To find out if yours is one of them, consult this list: http://www.motorhomemagazine.com/dinghytowingguide/
If you have an automatic, and your car is on the list, you can shut the engine while moving.
If it is not, do so at your own risk. You may still benefit from shifting into neutral (engine on) when coasting downhill or towards a stop, depending on whether or not your car has automatic deceleration fuel cut off (DFCI) built in (many newer cars do).

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Yerboogieman says: Dec 15, 2012. 11:11 PM
I removed the back seat in my Saturn, but as I was doing it, I realized it weighed a whole 10 pounds. So I eventually put it back in when I needed it and never planned on taking it back out. I checked my fuel mileage a few times and it really didn't help much. It might on my Suburban, as it has a huge frame, where the Saturn frame is built into the chassis.
ImageMaker says: Nov 29, 2009. 7:24 PM
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).
JacobAziza (author) says: Nov 29, 2009. 8:32 PM
"19A NCAC 03D .0535  STEERING MECHANISM
1. The inspection mechanic/technician must raise vehicle to get beneath to
check steering mechanism.
2. The steering mechanism shall not be approved if:
(a) With front wheels in straight-ahead position there is more
than three inches of free play in steering wheels up to 18
inches in diameter or more than four inches of free play in
steering wheels over 18 inches in diameter. If vehicle is
equipped with power steering, the engine must be operating.
(b) Either front or rear springs are noticeably sagging or broken, cut,
heated or removed/missing.
(c) The front wheels or front-end assembly is bent or twisted or bolts,
nuts or rivets are loose or missing.
(d) Power steering system shows visible leaks or the power steering belt
is loose or worn or missing.
(e) Shocks and struts are part of the steering mechanism inspection.
(f) The CV joints make a popping or clicking noise when vehicle is
driven into inspection area.
[A torn, worn CV boot is not justification for failure]"

http://www.ncdot.org/DMV/vehicle_services/emissioninspection/regulationsmanual/download/CR435NCDOTEnforcement.pdf

Nothing about changing power steering to manual.

Can't always trust what people say without sources, not even official people.

It wouldn't really make sense: I used an OEM manual steering gear from the exact same model vehicle, which means it is identical in every way to those versions of my truck which came that way stock.

I have only had r&p in very small vehicles (the truck is recirculating ball), so I can't comment on the potential feedback issue.

ImageMaker says: Jul 1, 2012. 11:00 AM
Wow, I didn't see this comment until just now.

Any case, R&P isn't only in small vehicles these days; it's cheap to make and easy to align, plus more compatible with near-universal MacPherson strut suspension. My Aerostar weighs about 3500 lbs empty, and has R&P (and, with the steering pump recently failed, is a bear to maneuver at low speed). Sure does pick up some pep without the pump, though, strongly implying I'm saving some fuel.

The clause "or the power steering belt is loose or worn or missing" is where they identify and fail vehicles that have had the power steering removed -- they'll have an empty pulley on the crankshaft and coolant pump, at least on multi-belt (older) vehicles; newer cars that use a serpentine may be impossible to match a belt for with A/C or steering pumps removed. Then again, different inspection stations adhere more or less to the letter of the law; one I used to go to failed me for a leak that didn't compromise function as long as I filled the reservoir regularly, another (the one I use now) won't, as long as the assist is working.

Beyond that, if your vehicle was originally sold with and without power steering, and you can document that, you should be fine. The same mod on my Aerostar would result in 100% inspection fails, at least with more "to the letter" inspection shops.
Inswitch says: Mar 5, 2012. 11:19 AM
Doubling mileage, not too shabby.

On octane, it's best to try 87 and 93 in your vehicle and do a 5 tank average of each to see which gets mileage. A blanket statement of the car being made for 87 won't benefit from 93 is not a good one to make. If tuned for the higher octane (advance timing 2-3 degrees) you may find that you get enough better mileage off 93 to more than offset the added cost. More modern, computerized vehicles have multiple octane tables that do this automatically. When the engine is started it will try the high octane table, if knock is detected it will revert to the low octane table. This is fact, I have software that allows me to reprogram my computer (EFI Live) and have altered both tables. Remember that the OEM has their own formula for setting up the engines that covers the widest range of uses, and their formula isn't necessarily the best one for your needs. I'd also recommend trying this with different brands. I have had vehicles that will get better mileage with brand A than brand B, but a second vehicle will get better with brand B than brand A, and still others that didn't care what was in the tank. I've even had two otherwise identical vehicles prefer different brands, so this needs to be checked on a per-vehicle basis. Remember when testing that fuel formulations change in spring and fall, and this will impact efficiency.

If you don't mind digging into the engine, a camshaft swap will also help. OEM cams are a balance of power, fuel economy and emissions requirements. A cam that is weighted more towards fuel efficiency would benefit. It may no longer pass a mandated pollution test, but those tests are set conditions. A vehicle that uses less fuel per mile is going to be emitting less pollution per trip.

I tried the acetone. It only worked for 1 tank, after that saw no difference. 1 tank is not enough to say it helped, so in my experience acetone does nothing for you. Once again though, different vehicles will act differently, but it was really a big pain in the backside making sure there was always some in the car.
JacobAziza (author) says: Mar 5, 2012. 3:37 PM
Thanks for that information.

I've never actually owned a car new enough to have a computer, so I would have never known or thought to try that experiment.
cbckidatheart says: Mar 14, 2012. 8:14 AM
Great article, I have a 1994 pickup that I want to try a few of these things on. Something that should be mentioned is that even though new trucks can get up to 25 mpg now, it cost so much money and energy to have a new car built, shipped and purchased. Which is hard on the environment, yet there are thousands of cars going into the yard each year that only need a few parts. Current cars on the road longer and making them more fuel efficient is a great way to start an eco friendly movement.
earthwindwater says: Jan 27, 2012. 8:57 AM
Thank you for explaining the Alt delete!
JacobAziza (author) says: Jan 27, 2012. 9:18 AM
ok, there is no way to upload pics through ecomodder pm, so send me an email
biodieselhauling (at) gmail (dot) com
JacobAziza (author) says: Jan 27, 2012. 9:08 AM
Welcome, glad it helped someone
I'm guessing your the same person who PMd me on EcoModder?
I got your message, I'm going to take a pic before I respond
dragonriot says: Dec 20, 2011. 1:20 AM
I'd really like to know how much this guy spent on "Converting" his truck over time. I drive a 94 Yukon 6.5L Diesel, and I know that my current 17mpg average would go up to 36mpg with a Cummins 4BT swap.
JacobAziza (author) says: Dec 21, 2011. 7:55 AM
I assume "this guy" refers to me?

2 sheets of coroplast (grill block, underbelly, and sideskirts): $40
tonneau: $120
wood sides to tilt tonneau, from scrap wood: free
headlight covers: $10
electric fan: $15
electric vacuum pump: $290
manual steering gear: $50
buttons, switches, wire, misc: about $20
LED lights: $180
-----------------------
Total: $725

I may be forgetting something, but certainly under a grand all in all.
Based on how much I have driven in past years, the cost of fuel, and may change in average mileage, I should save about $2000 per year in fuel costs.
Assuming I spent all the money for downgrades upfront, it would have paid off after 6 months, (though of course this project was drawn out over about a year and a half)

Thanks for asking! Believe it or not, I actually never got around to putting all the costs in one place before. Its good to know.

Rportal says: Jul 25, 2010. 4:53 PM
Driving slowly is illegal. It is called impeading traffic and you can be cited. Just so you know.
JacobAziza (author) says: Jul 25, 2010. 5:38 PM

Driving slowly is not illegal in a single state in the US. The posted speed limit is, without exception, the UPPER LIMIT to how fast you are allowed to drive. It is NOT a mandate that you must drive that speed, it is NOT a recommendation, and it is most certainly NOT the lower limit.

If you deliberately came to a complete stop on the highway, then you are impeding traffic.
If you were, for example, driving 15mph in a 65 zone, you could be cited for a number of things.

However, even then you are not actually impeding traffic, because on a multi-lane highway, people can just change lanes, and on an undivided country road people can pass in the oncoming lane or at turn-outs.
On city streets or mountain roads where it is not safe to pass, it is also not safe to drive 65mph, so there is no problem.

No where do I suggest driving 15mph on the highway. Below around 45 or so (depending on the vehicle) you have to shift into a lower gear, and therefor your mileage drops off.

There are some (not all) states in which there is a minimum speed limit on some highways. When there is IT IS CLEARLY MARKED ON EVERY SPEED LIMIT SIGN.
In Michigan, for example, on some freeways with a 65mph upper limit there is also a 45mph lower limit. This means you can go 20mph slower than surrounding traffic (that's assuming no one is speeding)

Bottom line is, you NEVER have to base your speed on what people around you are doing. If every single person on the highway is speeding, except you, then every single person on the highway is breaking the law, and you aren't.

Don't just make up stuff that you wish was true. Almost all laws are posted on the internet, so you can find and cite the exact vehicle code you want to inform people of, instead of spreading false rumors and confusing people.
dragonriot says: Dec 20, 2011. 1:14 AM
Totally not true about posted minimum speed limits. Wisconsin has a 45MPH minimum speed limit on all Interstate Highways (I-94, I-43, etc) and it's not marked anywhere on any highway sign anywhere in the state. It is the same whether you're on a 65mph zone, or a 55mph zone, 45mph is the minimum. Of course, if the MAX limit is lower, then the minimum limit is lower as well, but there's no point in going 35 in a 45mph zone.
JacobAziza (author) says: Dec 21, 2011. 7:38 AM
I'll take your word for it and stand corrected.

I don't know of any modern vehicle which has max efficiency at a speed lower than 45 anyway, so there's no reason to go below that.
freddysserpent says: Oct 17, 2011. 11:03 PM
actually it is up to police descretion as to what is an impedment of traffic (which you can be charged for) and their working model is different state to state but if you stay within 20% of the limit(depending on conditions) you won't have any problems. Oh by the way you can be charged for driving at the speed limit as well if the conditions are bad. It is called negligent driving (for not adjusting to the change in conditions). Unfortunatly if you are charged with either offence it is difficult to fight in court as I know from personal experience ( I was lucky that I hold a raceing license as well therfore my knowledge and level of expertese was considered better than the police officer's involved )
vincent7520 says: Nov 4, 2011. 9:25 AM
Back to hippies days ! … Far F… Out !!!!…Get rid of everything ! …


:D :D
swoopsdad says: May 12, 2009. 1:01 PM
Actually, having been in the automotive industry for almost 20 years I feel the whole tonneau cover, tailgate up or down aerodynamics issue needs to be put to rest at last. When the box is empty the most fuel efficient state is without a tonneau cover and the tailgate(solid) in the up position. This is because the truck has a bulit-in laminar airflow to it when empty and in this configuration. Simply put, this means that the airflow created in the bed of the truck acts like a cushion to keep the airflow from the front above the bed until it gets to the rear bumper. By putting a toneau cover on(or leaving the tailgate down) it disrupts the laminar airflow creating downwards pressure on the bed(or rails) of the truck. This results in a higher drag coefficient and therefore higher gas consumption.
pddonovan2011 says: Sep 4, 2011. 1:39 PM
You are correct, there is only one modification that could be done that would make the 'tailgate up/bed empty' mileage even better! From the top of the tailgate to the bottom o the lowest part of the bumper make a perfect radius or half dome on its side. Create round Plexigalss or Lucite covers with this same radius to cover the side taillights and you will complete the laminar flow on the tail will Actually be pushed along at highway speeds!
zolar1 says: Jun 17, 2011. 2:45 AM
This would be vehicle specific. I have a 2009 Ranger. Tailgate up - 18-20MPG.
Tailgate down - 24mpg.

Oh, Mythbusters has been caught outright lying about a great many things. And intentionally skewed results from a lot of other things as well.

Great entertainment, but please do not believe anything they say. They do it for entertainment value only.

BTW, how come no one has done an experiment with the tailgate removed?
And another one with those cargo straps for a tailgate?
pddonovan2011 says: Sep 4, 2011. 2:23 PM
I HAVE, how's this for vehicle specific!
2003 Chevy S10.
I have an iPhone App that reports real time MPG via the OBD2 port.
No tailgate, 29.8 mpg!
With tailgate, 30.3 MPG!
With hard Fiberglass Bed Cap 30.7 MPG!
With thin Plastic vehicle specific,'Cab-hi Shell, 30.6 MPG.
With the tailgate and the Shell Hatch removed, 30.8 MPG.
With a round tail-cone installed and sealed to the rear of the bed and shell, lots of duct tape!, 31.2 MPG.
These tests were made at the same time, during the same commute, down the same highway and reflect the average collected during a FULL WEEK of commuting for every result!
The Saturday before each of these weeks, the battery was disconnected, overnight, to reset the computer in the truck. This way the computer relearned the trip for that week. The ONLY modifications made were to the rear of the truck.
I have not yet tackled the front of the truck! I could change the grille, the head lights, use clear tape to seal any 'dirty' gaps. remove the windshield wipers. I could really go nuts with this stuff! But the truck has the 4.3 V6 and Over-drive Automatic. I KNOW I am doing damned good with the MPGs I am getting!
FuzzyBearGeek says: Aug 14, 2011. 2:07 PM
omg. Are you one of those paranoid type people? They do it for entertainment porpoises only? Wow. Floored.
Do you believe dinosaurs didn't exist too?
zolar1 says: Aug 14, 2011. 9:24 PM
LOL. Of course dinosaurs existed.

But Mythbusters is strictly an entertainment show, nothing more.
Fun to watch them blow up stuff.

And no, I am not the paranoid type. I am more of a doubting thomas of sorts.

If I cannot recreate their experiments with the same or very similar results, then their show is a farce.

There have been complaints with them about some of the things they show.

Maybe googling 'mythbuster lies' could be of use?
JacobAziza (author) says: Aug 15, 2011. 8:14 AM
I think "lies" might be going a bit far.
Sure, it is primarily entertainment. And they don't always follow scientific procedure when it isn't convenient.

But they do deserve credit for bringing the concept of "don't take someone's word for it, actually try it" to a more mainstream audience.
As a "doubting Thomas" myself, I appreciate them for that.
JacobAziza (author) says: Jun 17, 2011. 7:46 AM
How did you control for variables in your tests?
How many miles did you do for each one, and under what conditions?
What method did you use to measure mileage?
13blue says: Feb 6, 2011. 11:40 AM
There was a great "Mythbusters" on this that proved the same thing. Empty bed with the tailgate up was the way to go. Also the windows up with the air con on is more efficient that with the windows down. I had to adjust my driving for both of these.
JacobAziza (author) says: Feb 6, 2011. 12:16 PM
The problem with the mythbuster episode is that they only checked one specific model of truck, when there are many different variables of truck bed length, cab length, cab height, overall truck length and height, and cab aerodynamics.
So they really only proved it for that specific truck.
There have been other people to test and get different results. They just didn't have a popular TV show!

Anyway, what I have now is more aerodynamic than tailgate up, down, or flat tonneau, making the issue moot.

As to airconditioning, you get the best efficiency of all by having the A/C off AND the windows up. Put a beaded seat cover over white seat covers, tint the windows, paint the roof metallic silver, take off any excess clothing, and open the vents.

FuzzyBearGeek says: Aug 14, 2011. 2:08 PM
I love your brain. :o)
kikiclint says: Jun 27, 2009. 3:14 PM
I have been turning my truck off going down hills on the free way. I can definitely tell a difference when I have my canopy on. It slows me down. With it off I have to keep my foot on the breaks to stay in the speed limit.
joeofloath says: Jun 16, 2009. 1:59 AM
That is true of newer vehicles, but remember when this truck was designed, aerodynamics weren't even tested. The first regular (IE not a race/performance car) car to really be looked at from an aerodynamic perspective, as far as I know, was the European Ford Sierra. In older trucks, It would be more efficient to keep the tailgate up and use a tonneau cover.
JacobAziza (author) says: May 12, 2009. 1:09 PM
Most of the time the bed isn't empty. We have already gone over this in the comments.
bahi says: May 16, 2011. 2:17 PM
I admire you work and effort. I wish I could do the same here in Spain, but such radical modifications are illegal.
But one of the most important things we all can do is driver slower, it saves fuel and the most important thing, lives.

Max speed has been temporary lowered here from 120km/h to 110, and most of the people are raging against it, it's sad to tell, but most of the people don't really care about Self-sufficiency, environment or other peoples lives...

Anyway thank you for your great instructable.


p.s. I have a pickup too but I also ride a 250 bike or bicycle to work :)
JacobAziza (author) says: May 16, 2011. 6:10 PM
Thanks for the feedback, and for all you do.

In the USA we no longer even have a speed limit! We used to, at 55mph (89km/h), but it was repealed for no apparent reason in 1995.

Unfortunately, it didn't have the positive effects on fuel and lives saved was smaller than it could have been, because the law wasn't enforced.

Better than simply lowering the limit, if government really wanted to help save lives, reduce dependence on foreign oil, and ensure citizens respect the law (having a law and not enforcing it just tells the people they can do whatever they want) all they would need to do is have automatic radar/camera systems which send speeders tickets in the mail, in much the same way as bridge toll violators.

I really can't think of any drawback, other than whatever politician proposed it would be very unpopular.
thisiskaleb says: Apr 11, 2011. 2:00 AM
Will switching to premium gas help? I've heard that it burns more efficiently but doesn't work well with older engines. My old Corolla lost a good bit of mileage when I tried switching, but come to find out it was on its deathbed anyway (500 miles a day delivering pizzas didn't help.) Now I'm driving an '86 4Runner with a rebuilt engine (about 18,000 miles on it) and wouldn't mind some insight on the topic and what factors come into play when burning a higher octane fuel. And btw, GREAT INSTRUCTABLE!
JacobAziza (author) says: Apr 11, 2011. 7:27 AM
The main difference between premium and regular is its resistance to spontaneously exploding. Regular is "more explosive" and will tend to fire off before the spark goes off - in a high performance engine. 
That will cause an engine with high compression ratios to run poorly.

In a normal engine, there is no benefit to using high octane fuel.
In fact, it may run slightly less efficiently, because technically lower octane fuel has slightly less energy per gallon (very slight).


justinRgray says: Apr 7, 2010. 9:38 AM
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
JacobAziza (author) says: May 14, 2010. 3:59 PM
You know, the ironic truth is, I now find driving so much more fun that I probably drive more than I used to.
The whole interactive experience of watching traffic and lights 4 blocks ahead, paying attention to road grades, speed, gear, battery voltage, etc, figuring out when to coast and when to reengage engine, its almost like racing, except instead of maximizing speed, you are maximizing mileage.  Its a challenge, and I get excited every time I work out the numbers at the pump and I got a little bit further than last time
morbidmx says: Nov 4, 2010. 1:19 PM
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
nerys says: May 20, 2010. 11:26 PM
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 :-)
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