Ideas to increase F350 MPG (DIY Cyl Deact?)
 

Hello All!

I have a 96 Ford F350 4x4, 7.5l (460), Manual with MAF.

I have another vehicle for daily commuting and non-hauling needs. But when I go to haul with the truck most of the time I am nowhere near maxing out the hauling power and I would like to get some more MPG with little loads and when going to pick them up.

I got this truck because I will soon be moving out to my cabin and hauling my own water which will effectively use the power of the engine, and when Im hauling a near maximum towing load I dont mind low MPG. However often times when hauling a light load or going to pick something up and I am empty I would like to see if anyone has any suggetions to increase MPG.

I am currently tuning up and refreshing all the components of this old truck. I also am driving using as many hypermiling techniques as I feel comfortable with. Many suggestions such as aero covers, or weight reduction, etc are not possible as this is a work truck. I would just like to see even 15mpg when empty haha.

The only thought I have had and please let me know what you think is a DIY cylinder deactivation. Now I see many threads on that, but I have a different idea than other threads I have read and intereted in your input. First it would be a purely electrical bypass setup as I do not want to mess with engine internals and sadly there is no bolt on kit to purchase for this engine. Im thinking adding resistors and bypass contacts to all of the fuel injectors as well as the (2) o2 sensors and having a small control panel in the cab. So I envision a switch that is power mode and economy mode. Power mode is exactly what it is right now stock. Economy mode will engage the o2 sensors resistors to fool them into reading a perfect a/f ratio (this i think is needed since I will not be closing off cylinders and the extra air from them will give the sensors a false lean reading and dump in extra fuel to compensate negating what im trying to accomplish). At the same time I will engage half the fuel injectors resistors (exact cylinder numbers to be determined) so half of the engine will not be getting fuel. Now I also envision some sort of relay or timer that will switch between half the injectors and the other half every cycle or every minute in an attempt to keep the wear and temps even.

Firstly I am interested in opinions on the concept only for the time being. The exact relay or programming logic to sucessfully switch between injectors can be determined later on as well as which cylinders to deactivate at one time.

Also I understand there will be pumping losses with this setup. As I stated im not interested in fabricating my own hardware to completely shutoff the valves to a cylinder.

So what do you think?.. Is it at all a sound proposal? Will the pumping losses to be too great and not worth any of this effort in improving MPG? Also I understand by cutting half my injectors I will not be getting 2x my MPG, but in your opinion what increase could I expect? 10%, 20%, 50%? If the increase is not enough then I am not much interested in pursueing this option.

Thank you all very much!!!

1. Cylinder deactivation REQUIRES valve deactivation. Without it you can expect minus numbers for mpg improvement.

2. 460 Fords get the same mpg fully loaded or completely empty.

For cylinder deactivation to really be worth it you need to be able to collapse the lifters and close both valves in the cylinder. With the valves opening and closing trying to move that air in and exhaust out it feels like the engine is misfiring badly.

What I did to double fuel milage on my carbureted suburban is:
Tune the engine for lean burn during cruise, lean at or near WOT is bad, you need to run rich during higher power situations.
Adjust the timing properly, does it have EGR?
Use EOC.
In the winter I took the fan off my engine to speed up warm up times and I am going to switch over to electric fans. In AZ, during the summer in the city an electric fan may not be a good option for you.
I also made a switchable warmed thermostatic and cold air intake, the thermostatic side is too small for WOT use.
With fuel injection you should just be able to use a traditional warm air intake.
You can change to a numerically lower rear end too.

It's 4x4.

I have always said that 4x4 is more expensive.

Cuz he'd have to change the front axle too.

Change tires to a smoother road tread, something that you can put higher pressure into. If you increase the tire circumference you effectively do the same thing as a rear end reduction (except that most larger tires weigh more). Pull the mirrors in when you know you will be on the highway. Partial grill cover perhaps. Remove any aero-no-nos like cab shades and bug deflectors. If you have construction skills I would say build a 3 foot folding partial fishtail (top teardrop) attached to your cab roof and covering your bed partially when you can. It could fold down against the back window, or perhaps fold up over a load. You could also build partial side shouds but I am not sure if any of this would make much difference...be fun to experiment though.

Lots more work, nothing to show for it. Even light P&G is an exercise in futility with these pigs. Smoothness and throttle precision are your main tools here.

The only good news is that it's a 96, so an SG or UG should work- unless HDs were somehow allowed to slide for a year or so from OBDII. With instrumentation, all the standard benefits apply- FE isn't simply abysmal, you can see exactly how abysmal it is and make slight tweaks with foot placement and gear selection.

That's not entirely correct- the other bit of good news is that it's a manual.

There is aero you can do that won't affect the bay. Smoothing out the underbelly with coroplast panels or making moon covers for your wheels should help a tiny bit.

A kill switch for EOC... I can't see why this wouldn't be helpful, especially on down-hills. Do the injectors cut off when coasting in gear?

Clean the dpfe and egr valve, it's an old ford, that's like half of your mpg if equipped.

Edit, I read further. Its a 460, if it has egr, clean it twice. Helps for economy mode/lean on cruise/ mpg highway mode whatever it's called. I'm guessing it's "heavy duty" if it has an economy mode after 1996.

Side note, I've noticed old escorts like having 10-20% ethanol, no clue on the 460's but they are so sooty, that even if there is no mpg gain like an escort, the carbon removal is good on occasion. Different bores/strokes obviously, but I like all fords with D-shaped heads.

1. True, as proven by experimentation and a realistic understanding of pumping losses

2. False, as proven by experimentation and a realistic understanding of the conservation of energy.

Yeah, you'd sure think so, but it seemed that F250 always got 13 mpg NO MATTER WHAT. All my other smaller-engined vehicles showed noticeable mpg variability due to loads and conditions.

Then it wasn't sufficiently loaded to require the production of more power to perform more work which would invariably require more fuel. A tank average might not show it depending on the use of the vehicle but science works every time.

Duh

You'd think so...

Allow me to rephrase: F250 driven empty = 13 mpg. F250 pulling triple axle trailer and 14,000 lb John Deere tractor = 13 mpg. Tank-to-tank calcs. Could be fill errors. Pre-gas logging era. But very minute mpg variation just the same.

P.S. Truck totalled about 15 years ago. Cannot retest. Sorry.

Thank you for your valuable time.

My father has a 2001 that gets 13MPG. It's a 5.4 with 4.10 gears.

However, towing a trailer that weighs 2000-3000 pounds, it jumps to 15.

Trailers can mean a lot more DFCO. Even if you don't have it, their inertia can mean a lot less load at times.

Yes, DFCO can increase significantly with a trailer as can aerodynamic efficiency as the trailer fills in the tow vehicle's wake. Especially evident when I haul the Lance slide-in camper and tow an enclosed cargo trailer compared to the camper alone.

https://cdn2.commercialtrucktrader.c...300&height=225

You should find something like this. I would also put a boat tail on it that could serve as storage for the bikes.

Or maybe this. Already has a door and windows. And 134K is almost broken in for the 7.3

https://cdn1.commercialtrucktrader.c...300&height=225

I think with the right ecu (from say a dump truck or something emissions exempt, or better yet custom) 460's, 4.9l, and 1.9l fords they all have a habit of doing a weird high NOx thing while pumping egr.
Very sooty, very little mpg loss under load. Crazy timing, and flame speeds going on in those high swirl heads.... But that's waay over my head.
HONDA AND FORD ARE FINED MILLIONS - NYTimes.com
If people feel so inclined, there's a few articles between 1993-1994 where independent researchers were testing a lead substitute for a test blend of fuel (I forget the additive and I lost my links) but the escort was clogging the egr system very quick, and the escort was using "inappropriate enleanment strategies", which blew the lid off of the 91-95 escort ECU's, mainly egr equipped models, but then the 4.9 was found to do the same, and the 460 was usually exempt. But the point is that the torquey fords pre 96 and the 97 Econoline, were pulling a Volkswagen on the EPA. Savage.

A base map shows nothing over 15:1 on these engines, but they cruise at 17+:1..... Fishy.... But I'm not complaining :)

If the O.P. wants cylinder deactivation, they should hope for an egr valve, clean the dpfe, and clean the valve itself. Just my .02

No offense but this guy has a MANUAL TRANSMISSION.

If he can ensure that his 4WD stays unlocked and in 2WD mode he should be able to P&G without damage to his drivetrain.

That is likely the only way he will move his FE, coupled of coarse with a kill switch.

One thought:

If you're using this rig's hauling capacity mostly for schlepping in your drinking water, consider adding a rainwater harvesting system to supply your laundry and toilet flushing needs, and create a separate water circuit for those.

NOTE: hot water concerns. I don't have them since I never use hot water in the laundry, but you do you.

Eliminating some of those loaded runs couldn't be a bad thing.

And finally, consider getting a little ecobeater for when you aren't towing thousands of pounds of water. Getting decent mileage in a big bruiser is nice, but you can get decent mileage in a little scootabout too, and that's before you make any mods to make it even thriftier.

I second the vote for a water catchment system. Check out earthships. In the deserts of Arizona they are able to gather enough water just from the roof. It is like hypermiling for a house. The water is first used for washing then is held in a grey water tank for secondary usage in toilets and garden. Not everything earthships do is genius, but the idea of catching rainwater could save you a lot of trips to get water. Heck, done right you might just have to haul a few 5 gallon tanks for drinking water.

Getting back to the 460 mileage. May everyone who argues that empty mileage has to be better than loaded mileage, scientifically, be awarded an old Ford 350 crewcab, 4 wheel drive, 460, with a grabby clutch and weak syncro as their daily driver in city traffic. And then they can check it out themselves.

I dunno, my Dodge Ram auto crew cab can get the same mpg as the op, but even with an auto, I can move the mpgs from 8-15 up to 16-22 by eoc and occasional p&g with slow driving in overdrive.

Other option would be to remove 460 and put in a kubota diesel, 300%improvement in the mpg metric.

Meh. 1993 F350 CC DRW 7.3 IDI and ZF5 mileage actually increase from empty to lightly loaded, or empty with the AC on vs AC off because the big diesel just wasn't being worked hard enough empty to burn all the fuel the mechanical injection was using. Beyond that point though, mileage was flat until either the hay trailer was loaded (weight + drag) or the 5th wheel was hooked up (mostly drag). I get that a big engine not working real hard isn't going to see major MPG drops at moderate loads, and especially not DD'ing, but I assure you, from considerable experience, if you get enough of a load behind that truck it'll start burning more fuel.


With regard to getting it to burn less, you can advance the cam timing with a "straight-up" or adjustable timing set, to offset the retard built-in by Ford as mentioned previously.

I also suggest to be water independent will save a lot more. Here are some suggestions beside googling Water Harvesting.
Before Permaculture: Keyline Planning and Cultivation

Here is a man that produced a food forest in the deserts of Jordan in salty land and after 7 years of being abandonment he came back to look at it and it was thriving without irrigation. https://www.youtube.com/watch?v=reCemnJmkzI

Since 1920's it was discovered a source of very deep water planet wide that is fresh and endlessly flowing once tapped and many times under 200 ft. It is tapped into rock fissures where it travels up. Called primary water
http://primarywater.org/

good luck

My Dad's old 350 cu in Chevy Cubevan got the same mileage, +/- 2mpg whether running empty or loaded with 2 tons of electrical supplies, if driven at the same speed. He drove it empty with a cabin trailer behind it from Toronto Ontario area to Bakersfield Ca, then back with the truck loaded, as well as more weight in the trailer. He may have driven a LITTLE bit slower with the load, but knowing my old man "swervin' Mervin" I doubt it. He used within $10 of the same amount of gas coming as going.

I also had a 1976 Dodge Ramcharger that gave better fuel consumption with the plow on and pushing snow in the cold than it did cruising around town in the summer. The harder that 318 worked, the happier it was.

My 4 liter Ranger can squeeze about 30 MPG (imperial) out of regular unleaded, or it can slurp it through at the rate of about 9 or 10 MPG - both without a load - so I imagine hauling a load would not make it any better.

My old mini did an average of 49.6MPG over the roughly 20000 miles I drove it - and I used the throttle like a switch. Don't think I ever got over 50, or less than 48. The only car I ever drove that went faster in 3rd than 4th - all 850CCs were going at full gallop all the time.

That means it was nearly at full load just from aero drag.

I had a 460 powered E350. About 7 unloaded and high 5's loaded.
I'm going to guess that any sort of cylinder deactivation will never pay back.
How about a motor swap?

As far as engine swapping Ford trucks goes I have always been told not to.
Might be better off with a gear swap and tuning.

you gotta quit listening to whoever told you that

I once helped put a 12 valve Cummins in a beloved F-350, wasn't a huge deal, but there isn't much controls on a mechanical injected Cummins.

No, it was FAR from fully loaded from drag alone - it was just not tuned for economy. The old 4BBL carb was like a calibrated fuel leak (back about 1975?) and emissions control was in it's infancy.

Another Chevy V8 gas guzzler was a friend's G3500 van that he towed a 35 foot trailer with from Toronto area to Texas and back for several years. One weekend we drove with him to Elicotville New York. It was a $200 trip for gas alone, and the foot was buried all the way (with very little chance of getting a speeding ticket). After opening up the TBI unit it used about half as much gas towing the trailer, at less than half throttle, and was capable of a lot better cruising speed. An RV cam and bigger exhaust the next year made even more difference - but the next year he blew it up - it had a LOT of real hard miles on it.

Some of those engines were not tuned for economy, and poorly tuned for power as well. The 385 Ford (370, 429 or 460 cu inch)engine family was one of those. They were built for medium truck service where, at the time, fuel mileage was not a major consideration. They were built for TORQUE.

Any dreams of getting decent fuel mileage from a 460 in a 4X4 F350 are just that - dreams - without pouring in a LOT of money and effort.

right. I did not mean full load as in, all the drivetrain could handle, just that it was using nearly all the power it was making. Kinda like LOD on a scangauge, can be at 99 with the throttle barely cracked and making maybe 10% of max power.

Another friend repowered an F250 4X4 with a Deutz air cooled diesel for use in Belize. He had no more boil-over problems or plugged/punctured radiators after that. He didn't need the heater.

Other than the power wasted as noise or heat in the Rad and exhaust a vehicle pretty much always uses all the power it is making. It just isn't always making it very efficiently - -

If its in your budget, check out the cummins swap. Simple and reliable. I know being in AZ, a rainwater system isn't going to net you a lot. Keep it at 55, you might put some skirts on it, but beyond that keeping it properly tuned up will help. If you don't want to swap motors, might look into a supercharger/turbo charger setup. A 460 is great for its intended purpose. Not good for much else. :)