From 15 to 23.75mpg in a 5500lb work truck

[JacobAziza]

The following is from my blog, following the progress of my driving and vehicle mods since I first heard of hypermiling from the article about Wayne Gerdes in Mother Jones.

It was written for an audience which never heard of this stuff, so please forgive the unnecessary (for you guys) explanations

[JacobAziza]

Step 1, January 28th

My mileage results are in

I've been driving more conscientiously ever since I read the article on hypermiling, which I posted about in November of last year ("Some more stuff other people wrote")

I didn't quite take it to the extent of the guy profiled in the original article (he drives on the edge of the road to avoid the extra friction from the tire grooves, and knows exactly how far from home to coast to a stop exactly in his driveway without touching the brakes) but I did slow down, accelerate gently, shut the engine at long stop lights and coast down hills. There is even a 2.3 mile stretch of highway 13 (which I take on the way back from Bike Patrols) where I can put it in neutral, shut the engine, coast down one hill, up the next, back down, off the off ramp, around a tight curve, through a yield sign, back on to the freeway entrance for 580, off at the next exit, and down to MacArthur before starting it back up again.

In the past, on the motorcycle I have generally accelerated fast, just because its so easy, and so much fun, and because as hard as I drive on it, I've never gotten less than 50mpg. I stopped zipping about at 100mph+ after a couple accidents and a whole bunch of tickets, but I still would top 75 at times.
Since reading the article I kept the speed down between 50 and 55 on the highway, and stayed ducked down behind my big aftermarket windshield, out of the wind. It took a long time to find out the results, because it went so much farther on a full tank.
Where I used to average around 55mpg, on the most recent tank I got 70.2mpg, an increase of 28%.

In the truck I wasn't expecting to find a big difference. I can't as easily coast around since it uses loses both power brakes and power steering without the engine running. I was already driving at 55mph as it was, so reducing my speed to 50 didn't seem likely to have much effect. I already kept the windows up on the highway to reduce drag, and it doesn't have any AC to shut off.
Even so, from my usual 15-16mpg, it went up to 19.7 on the most recent tank, an increase of 25-30%.
Its hard to say how much its related to driving habits, because some days I am moving 3 tons of dirt, other days there may be a queen size boxspring sticking straight up into the wind, and others I am just moving a single 2-person love seat; but after almost a month and over 300 miles its likely to have balanced out.

So there you have it. In both the smallest most efficient vehicle you can find or a big old work truck that can haul several tons, you can save 25-30% on fuel by just making small changes to driving habits. If this gets out, it could just spell the death of the hybrid.

[JacobAziza]

Digression, March 9th:


A drawback of hypermileing

I've been driving around 50-55 on the freeway for the past few months, managed to get my '83 diesel f-250 work truck from a previous average of 15mpg, up to 19.5mpg (this is with various loads of furniture, boxes, dirt, appliances, etc in the back)

Last night on my way home, going 50mph, some cars merged very slow, and instead of accelerating to pass them, I slowed even more to let them in, but they were going SO slow I just moved to the left instead.

As I accelerated gently back up to speed I noticed a cop behind me, and just as I put on my signal to move back to the right, he moved to the right without signaling.
So I stayed where I was, and waited for him to pass on the right, still not having accelerated up to speed yet.

After a couple seconds, instead of passing, he pulled back in behind me.

And lit up the red and blues.

After answering a bunch of questions (last thing I ate was ice cream, 2 strawberries, and 2 almond cookies, I am not under the care of a doctor or dentist) I did a balance test, and when I passed that, took my first ever breathalyzer.

In an area where everyone goes 75, why would anyone drive slow unless they were drunk?

I told him I drive slow in order to save gas (and I was going particularly slow while I waited for him to pass - I didn't point out that he hadn't used his turn signal).
He said that I was going 20 under the limit.
I wasn't sure how pointing out that the "limit" was a MAXIMUM limit, not a minimum, would be taken, so I was just mostly quiet and agreeable.

No ticket.
I actually found the whole ordeal rather amusing, but I hope this doesn't become a pattern.

[JacobAziza]

Step 2; physical mods, March 21

My other project (trying to make my big commercial truck as fuel efficient as a car)

After being pulled over for driving too slow, I looked up a couple hypermileing websites in order to post the story among people who might find it entertaining, and possibly offer some advice as to how to avoid/deal with the situation should it happen again. While there I found all sorts of ideas and suggestions I hadn't thought of and decided to attempt to make the truck itself more efficient to compliment my new driving style. This number is totally arbitrary and baseless, but my "goal" is 25mpg.
The average fuel economy of all US passenger cars on the road (not trucks, SUVs, or vans) is only 22.
The overall mileage for all US passenger vehicles on the road is only 17 - less than I am getting currently.
(And that's "passenger" vehicles. Technically my 5500lb diesel is classified as a commercial vehicle, even if I didn't use it for work)

Of course this whole exercise is more just for the principal than it is to save money, considering how much I spent on the project so far.

Completed so far:

-I built some homemade wheel "skirts" (wheel-well covers) to improve aerodynamics. The current ones, intended just as a test (though I may keep them as is if they work well enough and hold up) is made of cardboard (the box my new computer came in), coated in layers of aluminum tape, and then painted and edged with velcro. I lined the wheel well with velcro, and stuck 'em together, then taped over the seams with clear tape to cover the gaps of a less than perfect measuring and cutting job.



-I taped over about half of the grill (the engine runs too cold as it is) and the front turn signals to improve the aerodynamics of the front which stock basically looks like a multifaceted scoop designed to catch as much air as possible.



-The headlights come in a little scoop too, but since it's vital that the light not be interfered with, instead of tape I had covers custom cut out of thin Lexan plastic, which is totally clear, scratch resistant, flexible, and nearly indestructible (the same stuff my custom motorcycle windshield is made from). I traced the headlights and brought the tracing to Tap plastics who were able to cut them for me in about 5 minutes. I drilled holes in the corners and screwed them onto the grill so I can easily remove them if a headlight burns out.



-I ordered extra bright LED bulbs for the taillights and tun signals. They are brighter than stock but draw less power. The 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. This power is generated by the alternator, which is powered by the engine, so any reduction in electric draw ultimately reduces drain on the engine.


(while the incandescent - left - fills the lens more uniformly, the led - right - lights up the surroundings and the edge of the tailgate)


(the difference is even more dramatic when the brakes/signals are applied)

-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 the same metal tape as my new rain gutters) 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 (plus it looks really cool). I also added a voltmeter where there was an empty space before (where a tach would be on higher end models) so I can monitor the batteries if I decide to build in an alternator cut off switch



While I was working in the dash, I accidentally snapped the end of off the speedometer needle. It was extremely brittle, and as I tried to repair it, I ended up breaking off the rest. I replaced it using a match stick broken in half with a sewing needle stuck in the end, glued and taped to the post where the old needle went. I choose a needle with an orange ball on the end to match the truck. I drove past a couple "your speed is" automatic radar signs to roughly calibrate it.



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 so that I can't possibly accidentally leave them on and drain the battery (which would be pretty bad if I'm running sans alternator).

-I installed a tonneau cover which, in addition to increasing the trucks aerodynamics, will keep small loads clean, dry, and protected, making it a (semi)legitimate business expense.



-I also ordered an air compressor - the one I had wasn't nearly powerful enough for my trucks large high pressure tires. The portable Viair which runs off the truck battery, actually fills my tires faster than any gas station or mechanic compressor I've encountered. In addition to the valve caps with built in gauges I installed, this should help me keep my chronically underinflated tires up to standard.


(the valve cap turns red when tire pressure drops)

-Perhaps most important of all, I ordered a couple bumper stickers to explain to people behind me why I am driving so slow. Hopefully this should encourage people to pass, possibly inspire a few people to slow down themselves, and maybe even decrease the likelihood of future breathalyzer tests.




Future ideas include:

-Wiring in a engine kill switch and push button start. While this won't make a direct difference, it would allow me to start and stop the engine faster and easier (they would be mounted to the shift lever) without wearing out my ignition switch which will make coasting downhill and killing it at stoplights much more convenient.
-Replacing the power steering system with a manual steering gear. My steering box is worn out and needs replacing anyway, so this may actually save money upfront (it should be cheaper) as well as reducing the drain on the engine by allowing me to remove the power steering pump altogether.
-Wiring in a switch to prevent the alternator from charging. I would then charge the large dual batteries at home each day. As long as I stayed with in the reserve capacity of the large dual batteries, I could run all electric systems off of grid power instead of fuel, but if I ran low I could always turn the alternator on (the power drain of the alternator can be as high as 1 to 2 horsepower)
-Replacing the stock hydraulic-clutch engine driven cooling fan with an electric fan which shuts off completely when its not needed (which is most of the time) moving one more engine draw to grid power (it would kind of make the truck a plug-in hybrid of sorts)
-Replacing the 3speed transmission with one with overdrive. They were used in later years of the same truck, and so used ones that fit perfectly are available, and from what I read, I think I could do the labor myself. With the current high gear, optimal speed is only about 35mph, and considering the experience I wrote about recently...

I have wanted a 5speed ever since I got this truck, but even used they go for $400 or more. It would take a lot of tanks of fuel to justify that.

On the other hand, by my calculations based on made up numbers (ie, assuming I can get 25mpg out it), I should get around 190 miles more out of each tank compared to before I first heard of hypermiling.
The 500 miles I'd get out each tank would require $75 worth of biodiesel, (currently a little under $4/gallon) instead of the $125 at the old 15mpg or $100 at my current 20mpg. 500 miles is (very roughly) how far I go in a month, saving me $50 a month.
So, now that I actually work out the calculations here, for this blog entry, it seems I may hypothetically make back what i spent in a fairly reasonable amount of time afterall. If I keep this job long enough (and I have no plans to stop in the foreseeable future) that 5speed just might be worth it too.

[JacobAziza]

Step 3, April 8th

Upgrade Update

If I really wanted to accurately determine how much difference any particular change made, I would make upgrades immediately after filling the tank, and then do only change at a time, going the entire tank and calculating mileage before doing another.
I don't have that kind of patience.

When I wrote last about it (the post with the pictures) I had begun those mods several days into a new tank of gas.

I looked up what was typical for the same model and year of truck online (there are no EPA estimates for it) and found people reporting anywhere from 10mpg to 18mpg.
Myself, loading it to it's max for work, but being a generally gentle driver, before I had ever heard of hypermileing I was getting between 15 and 17mpg.

By changing just my driving habits, driving slow, accelerating gently, coasting when coming to a stop, I raised it to 19.7mpg.

After the first stage of changes to the truck (the tank I was on when I wrote about them March 21) I ended up getting 21.75 miles with a gallon of gas.

Once again, I filled up, and then several trips into the new tank, got around to starting my next series of upgrades.
I still have yet to go to the salvage yard to try to find a manual steering gear and electric vacuum pump (so the brakes work when the engine is off). I was planning to go today, but the rain had me change my mind.

I did make it down to Al Lasher's last week for some switches.

Nobody makes a wiring diagram for this year for the diesel engine.
I spent many hours over several days upside down under the steering wheel, trying to trace and test various wires.

-If you happen to own a 7th generation (80s) Diesel F-250, and you want to wire in a kill switch or remote starter: The thick red wire with a green stripe goes to the injector pump (for a kill). The thin red wire with a blue stripe goes to the ignition relay (for a start).

The switches are dual purpose: wire them one way and they are momentary open, wire them the other and they are momentary closed. I used one each way, so that one stops fuel to the engine, the other triggers the starter. I mounted them side-by-side in a block of scrap wood, attached to the gear shift with a strip cut out of a steel can lid (mandarin oranges, of course).
As I had hoped, they definitely make the pulse and glide (coasting, etc) much faster, simpler, more precise, and safer, then using the key each time (especially since the ignition on this truck has been very finicky as long as I have had it) which encourages me to do it a lot more often.




-The orange 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.
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.
At first I just disconnected the wire, but now I have it on a switch so that if the battery ever does run too low, I can charge it with the engine just by flipping the switch.




-Another point of note: 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.

These have been my only changes. They facilitate they way I have already been driving, but do not, in them selves, reduce engine load or increase aerodynamics at all.

This most recent tank included jobs such as moving a full truck bed of bikes, bike parts, and tools across the windy Dumbarton Bridge




and hauling over a ton of concrete blocks, scrap wood, and plant debris on the freeway to the transfer station





As of my last fill up, my average mileage is 23.5mpg

Higher than the national average for all passenger cars on the road.
Higher than the average for model-year-2008 light trucks.

Next stop, eclipsing the average for all new passenger vehicles.

*EDIT*
6/02/09
Mission Accomplished:
http://ecomodder.com/forum/showthrea...-2-a-8613.html

[Daox]

Looks good to me Jacob! That is quite an impressive mileage gain. Its really great to see someone using a truck for actual work too!

[bennelson]

I just saw your posting on INSTRUCTABLES

Looks good! I especially like the headlight covers.

[JacobAziza]

I posted about that instructable somewhere on this forum; did you find it just by coincidence?

Anyway, thanks!
Still a work in progress - "wasting" too much time doing real work (i.e. the kind I get paid for) to be able to work on the truck lately.

[bennelson]

I saw the truck mod INSTRUCTABLE as part of the e-mail sent out by INSTRUCTABLES.

Then I came here looking for the same username, knowing it HAD to be an Ecomodder who posted it!!!

[theunchosen]

Jacob have you tried brewing your own biodiesel?

I am not familiar with your handle so I can't say anything leads me one way or another. You probably would if you could, but in the off chance you aren't aware you can make biodeisel out of used cooking oil from restaurants. Its just got to be filtered. My local restaurants will give the crap away(because up until biodeiselers came along they had to pay someone to take it). If possible hook up with a large chain restaurant because if the owner is not already doing it its money het gets to keep from saving the franchise money.

I've helped pull it from Cheddar's(like a bar and grill kind of, but with very inexpensive food) and it usually is about 40 gallons a week for free. You said you do about that many miles a week so you could potentially eliminate your fuel costs by picking this up once a week. You do have to filter it but it costs about the same as one tank of fuel for you.

As your truck is an older more durable model you shouldn't even have to mix hardly any(if any) diesel with your used veggie oil.