Video: Hypermiling a 1983 Ford F-250 Diesel?

https://www.youtube.com/embed/qBo7k_9zxBs

This 1983 Ford F-250 runs on biodiesel and features maximized aero. It returns fuel mileage in the mid-20s–real world mileage for this truck should be closer to 15 mpg. Truck owner Bakari Kafele also uses smart driving techniques in order to minimize engine load when driving.

So, what’s the most extreme measure you have taken in order to maximize fuel economy?

 

 

dculberson
dculberson MegaDork
1/30/20 10:13 p.m.

Just today I knew I would be driving much more than usual so I left the heat off in my Volt. Then I took surface streets home. Made almost 40 miles on all electric versus the usual winter range of about 25 miles. I'm not sure it was worth it, it was pretty cold.

buzzboy
buzzboy HalfDork
1/30/20 10:31 p.m.

Trying my hardest to hypermile my e36 with gentle acelleration, not using brakes, coasting in gear to cut injectors etc. I've managed 28.5mpg. Driving my BMW like a proper BMW owner, passing people and weaving in traffic, I managed 29.2mpg.

Respect to this guy. I am all about the small mods, maybe not going that far, but I get it. I've done a few things to the XJ and I'd like to do a few more for better fuel efficiency.

grover
grover HalfDork
1/30/20 10:57 p.m.

If I drive 65 in my 97 F250 powerstroke i can get 22.5. Pretty sure that it's less efficient to turn the motor off and on, especially on a diesel. 

Curtis73
Curtis73 MegaDork
1/30/20 11:00 p.m.

04 Duramax; 30-over injectors, 5-position chip with pretty aggressive timing curves, intake, exhaust.  It took highway MPG from 19 to 23... if I can keep my foot out of it.  938 lb-ft to the wheels is waaaay too tempting.  Nothing says "my hootus is tiny" like getting sideways in a 7000-lb dually 4x4 at 70 mph.

Justjim75
Justjim75 Dork
1/30/20 11:53 p.m.

In reply to Curtis73 :

That sounds like a E36 M3 ton of fun

spandak
spandak Reader
1/31/20 8:29 a.m.

My Boxster throws up numbers depressingly close to these... fuel economy blows my mind sometimes

infinitenexus
infinitenexus Reader
1/31/20 8:33 a.m.

I owned an E39 M5 some 7 years ago (still to this day one of my favorite cars ever) and I started experimenting with hypermiling on that car.  Sometimes I would turn it off at stoplights (if it had just turned red and I knew it would be a while), and I coasted downhill all the time.  I was usually able to average around 20mpg overall, sometimes almost 30mpg in the right situations.  When I drive my Mustang I still have the same habits.  It's like a fun challenge to me.  I still haven't been able to average 30mpg in my Mustang yet, but I'll get there one day.

 

In our plugin Prius one morning we left for work (wife and I carpool) about 20 minutes early so there was no traffic.  That way I wouldn't have people laying on their horns behind me when I practically idled up gentle hills at 18 mph.  That morning I averaged just over 100mpg on our commute to work of about 12 miles - and that included a 5 mile stint on the highway.  

alfadriver
alfadriver MegaDork
1/31/20 8:57 a.m.
grover said:

If I drive 65 in my 97 F250 powerstroke i can get 22.5. Pretty sure that it's less efficient to turn the motor off and on, especially on a diesel. 

Depends on how the engine is set up.  Most engines I've dealt  with have the best BSFC at pretty high loads, so if you accelerate at that output then cost with the engine off, in theory, you would be using the least amount of total energy to do that action.

 

mr2s2000elise
mr2s2000elise Dork
1/31/20 9:00 a.m.

My FJC is getting 15.7 mpg . Even with hyper milling 

 

my GSR sedan, I do 85mph and 60% 7500 rpm shifts a day. I get 21 mpg. When I act like a grown up, shift at 4500 rpm, keep it 80mph, tank average goes up to 26 mpg sometimes 

you will live once 

alfadriver
alfadriver MegaDork
1/31/20 9:20 a.m.
alfadriver said:
grover said:

If I drive 65 in my 97 F250 powerstroke i can get 22.5. Pretty sure that it's less efficient to turn the motor off and on, especially on a diesel. 

Depends on how the engine is set up.  Most engines I've dealt  with have the best BSFC at pretty high loads, so if you accelerate at that output then cost with the engine off, in theory, you would be using the least amount of total energy to do that action.

 

Watching the video- for sure he's using less fuel- the engine is off 3/4 of the time he's doing that.

In terms of start-stop- that I know works really well- I was shocked to see how much fuel that saved on a very simple cycle.  If he could dig into the controls of the fuel system, he could tweak the starting fuel to better optimize it- but given he had a start issue at a light, it's not a simple thing.  Old diesels like that have no MS kind of option to better set it up- which is a shame, as he could play with the injection timing to possibly gain some efficiency (since biodiesel does combust a little different than typical diesel).

I wonder if he's done some A-B comparisons for the electrical system- interesting to have it do what it does- but if he could control the actual charging system, you could easily use the alternator as an additional brake when the engine is off.

It would be interesting to see a truck driver who has converted to E85 or even E100 that is bio sourced (which is possible), and how much they could gain in terms of FE when they do the full conversion (MUCH higher CR, more aggressive spark, maybe lean burn, and then all of the hyper miling actions).

Toyman01
Toyman01 MegaDork
1/31/20 9:22 a.m.

If I baby the Silverado and piss off everyone behind me, it will get 19. 

The current tank is about 12 because my  time is worth more than any money saved. 

My father's 04 Dodge 2500 regularly returns 25 mpg in most driving situations with zero aero, and averages 12-14 pulling his 35' 5th wheel camper. Maybe the gent should consider updating his truck. The IDI diesels never were very efficient. 

 

Curtis73
Curtis73 MegaDork
1/31/20 9:47 a.m.
Justjim75 said:

In reply to Curtis73 :

That sounds like a E36 M3 ton of fun

It really is.  It's so linear.  Full boost is on by 2000.  It's not like a gasser where you slowly get pinned in the seat as you approach 6000 rpms, About 1 second after you mash the pedal, you're pinned... and you STAY pinned.

bcp2011
bcp2011 Reader
1/31/20 10:04 a.m.

Wow, respect for all the mods he's done for fuel efficiency.  

In my 14 Prius I can get ~45MPG doing 70 on the highway, 55MPG if I do 60, and 65-70MPG if I do 60 and find a big rig to draft.  That's the rough math for round trips (including startups where the engine runs to get the cat up to temp).  When I'm on the highway just drafting the computer seems to show 75-80MPG.  Aero makes a huge difference at speed.

Vigo
Vigo MegaDork
1/31/20 11:36 a.m.

It's interesting to say 'minimize engine load' because on a diesel that's different from a gas engine. Gas engines have throttle plates and the more closed they are, the more of the engine's power goes to pumping losses making all that vacuum behind the throttle plate. Generally when people get really serious about hypermiling gas engines they find a way to run with a larger than normal throttle opening to reduce pumping losses. That's tricky because you usually use that thing (the throttle plate) as your main way of controlling the engine, so making a way for it to run at a different load/throttle relationship usually involves some trickery of how to get it into and out of that 'mode'. 

 

Anyway, hypermiling mods are cool and interesting. I used to visit Ecomodders forum a fair bit and still open the occasional thread there. 

SVreX
SVreX MegaDork
1/31/20 11:47 a.m.

Mid 20’s isn’t magic in a 7.3L. I had a basic chip and no other mods- normal driving I’d get 22-23 without trying.

81cpcamaro
81cpcamaro Dork
1/31/20 3:36 p.m.

I would bet a turbo would help out on getting better mpgs on that truck. Mid's 20's while good isn't magic like SVreX said. I get around 22 mpg with my 6.5L TD K2500, and the 7.3L IDI I had would get 18 mpg in a 1991 F350 crew cab dually.

drainoil
drainoil Dork
1/31/20 3:57 p.m.

Don't think the 7.3 was offered until the late 80's. '83 would have been the 6.9 unless it was a swap.

My dad's mostly stock '03 7.3 can pull 20-21 fairly easily. 
 

Nothing wrong with trying to wring as much efficiency out of a big heavy truck but if mileage counts that bad one should probably get a small car if maximum mpg is needed.

Rushcanuck
Rushcanuck Reader
1/31/20 5:44 p.m.

last summer I drove my 2001 dodge 2500 cummins 5 speed... locked the cruise control at 95km for my drive down to the island (1100km each way) when I got back calculated out the mileage...30mpg... guess being gentle pays off

noddaz
noddaz SuperDork
1/31/20 6:15 p.m.

In reply to drainoil :

My wife has a 1981 F250 7.3 diesel non-turbo.  I have managed a best of 18 mpg with a fresh oil change and clean air filter.  Usually, 15 or 16 mpg.   I can't help think what additional power would be available if there was a better designed intake manifold available.  The stock one looks horrible, performance wise.  And someone does make headers for the non-turbo.  

03Panther
03Panther Reader
1/31/20 10:33 p.m.

In reply to SVreX :

Prior to 95, F250/350 diesels had no chip. Although in 94 you could get 3 different engines straight from the factory, and a fourth as dealer installed. A non turbo IDI (In-Direct Injection), a factory turbo'd IDI, and a Banks Turbo IDI. And just to confuse things, a few came with DI, turbo'd named the "Powerstroke" for marketing. From 99 to 02 (some in 03) all 7.3 were DI. The first 3, as well as the earlier 6.9, are all essentially the same, with mechanical injection. 95 changed a lot.

Although, I agree, his mileage "improvements" are less than can be done with less effort.

I had a 96 F350 dually, with the aerodynamics of a brick. Bone cold stock, with 114K miles and the smallest tire the factory offered. At 1900 rpm, on the interstate with cruse set, 28 mpg! 1900 is sweet spot for that engine stock. But that is doing 58mph! Using the pedal correctly at that speed would do even better, but would take a more patient man than me. Drive it like a "normal" person, 75mph, on cruse, 16mph. Load the truck and 12K lbs 5th wheel, and still got 12-14.

If someone can best 26-28, by turning on and off a stock engine - which is not good for the engine OR the emissions despite the lies "they" tell us - I'll eat my hat.

Yes extreme hypermileing CAN help in some cars, but at what long term cost? There is more in the game than pennies at the pump.

alfadriver
alfadriver MegaDork
2/1/20 7:19 a.m.
03Panther said:

If someone can best 26-28, by turning on and off a stock engine - which is not good for the engine OR the emissions despite the lies "they" tell us - I'll eat my hat.

Yes extreme hypermileing CAN help in some cars, but at what long term cost? There is more in the game than pennies at the pump.

Why do you think that?   For his cycle, I see no reason why it would wear the truck out at all- when he's doing the rolling shut downs, he's not using the starter, and the only wear item would be the clutch.  And given the age of the truck, there are no emissions hardware on it- and 5 second on + 15 off vs. constant running- it would be interesting to measure.  But the only real difference would be the NOx- and is it more than 3x more than constant?  Dunno.

I've measured it enough times to know it's not harmful enough to be a problem, and last I checked, there's not a huge number of cars failing with that feature.  Or am I one of "them" that you don't beive?

According to the video, he's claiming to save thousands of dollars a year- given he's a small hauling company, he puts a lot of miles on that truck, so whatever he does, the #1 expense is fuel, and all savings matters.  Perhaps he can save enough money to upgrade trucks to one that starts at 25mpg and can improve it to 35mpg.

The truck is an old POS that he's making into a very productive truck.  Seems like if it can survive, it's not really a durability problem.

Vigo
Vigo MegaDork
2/1/20 9:57 p.m.

 I can't help think what additional power would be available if there was a better designed intake manifold available.  The stock one looks horrible, performance wise. 

We usually get all of our intake manifold ideas from gas engines. That's fine except when we looks at gas manifolds we're typically not looking at what's a good manifold for.. sub-2300 rpm.  Even 'bad' gas engine manifolds don't start to really limit the engine until past an old diesel's redline.  Basically, old low revving diesels have really low standards for intake manifolds and the stock one probably doesn't suck as much as you'd think.

And then when it comes to diesels with turbos, a funny thing about that that most people probably don't consider is that if you take a set number of horsepower and achieve it with higher and higher boost pressure, the air moves through the manifold... slower!

 

03Panther
03Panther Reader
2/5/20 12:56 a.m.

Until recent years, an intake manifold did not mean the air filter.  The intake manifold on an IDI Iternational engine is not an inefficient casting. The air filter housing isn't the cats meow, but also ain't the choke point on a stock engine

I didn't look close enough to see if he had added a turbocharger, but that truck did not come with one. 

The info about the difference on gas/diesels/turbochargers is a good point

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