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How to get better fuel economy w/your diesel

133 messages,  Last post on Aug 27, 2012 at 11:06 AM

You are in the Diesels Forum.

What is this discussion about? Ford F-250 Super Duty, Dodge Ram Pickup 2500, Chevrolet Silverado 3500, Diesel, Truck

Messages Page 13 of 14

#114 of 133 Questions on my 2008 Ford F250 Crew Cab 6.4 Diesel by whoopbang123

Aug 04, 2008 (8:49 pm)

I also have a 2008 Ford F250 XLT Crew Cab 4X4 short bed, 6.4 Diesel with a 3.73 rear end. My first day of driving at approx. 65 mph, the vehicle averaged 9.3 miles to the gallon on the highway. One week later I'm averaging 13.3 on the highway at 65 mph. With a baseline of 65 mph on the highway, I've started researching various methods on how to increase my fuel mileage. My goal would be to reach or exceed 16-18 miles a gallon at 65 mph on the highway. Don't really know if this is due able but I'm trying. At this point Hypertech makes a programming device which will improve fuel economy by altering or tuning the motor for performance. So I purchased it. Additionally, I'm in the process of obtaining a new K & N Air filter that I believe will replace the stock air intake system on the twin turbo's. I guess my real struggle lies in the exhaust system or cat back. One person suggested I cut off the Particulated filter and run a straight pipe like a cat back. He said it will throw an error message but this can easily be reset. When I asked my muffler shop about this they encouraged me to keep the Particulated filter and just do a cat back. Any ideas on where to go from here? Or am I taking the wrong approach to this entire quest? tohocox.net

#115 of 133 Re: How to get better fuel economy w/your diesel [ladykathleen] by grbj

Aug 24, 2008 (10:10 pm)

Replying to: ladykathleen (Jun 24, 2008 5:10 pm)
Hi Fuel Economy for Diesels Folks
I came to your site looking for better fuel economy ideas, and see a lot of you ragging on the hydroxy approach. I personally have two 30 liters/hr units installed because I do lot of heavy pulling w my '97 7.3 liter F 350. The truck is not even broken in yet [only 38 k miles] but the cost of the fuel is threatening my retirement plans.
Since I am buying to equip a farm and develop property a hundred miles north, I do nothing consistently enough to develop a good set of comparative stats. But I do know many of you are not very well informed about what hydroxy purports to do. Let me make some points.
I have read that it would take 3000 lit/hr to idle a small engine, so adding only two percent to the air intake is not a significant power source.
1. Nevertheless, the addition of the hydroxy gas significantly increases octane, i.e., the number of the 8-carbon (chain) molecules in the fuel mixture. [FYI, methane is a molecule with everything attached to a single carbon atom, propane has three, butane four, and they all boil off the crude at different temperatures in the cracking/refining process. Any fuel is a blend of different percents of the different chains and related components, all of the pieces that make organic chemistry both highly complex and difficult. Thus adding pure (and purity is critical) acetone or zxylene to fuel in small quantities can really increase performance, or do nothing at all, depending on the mix in the initial blend.] Higher octane levels increase fuel combustibility.
2. Regarding the energy used in its production, the hydroxy gas is electrolyzed with the extra alternator capacity for winch use, cold weather, et cetera, but otherwise dumped via grounding circuitry to prevent over charging and damaging system batteries at other times.
3. Running the hydroxy gas through small water tanks has a double purpose. The water tank prevents random back charge explosions of the volatile gas in the generators themselves, but the various ions created in the [electrolysis] process also charge the water, letting its various vapors both aid in combustion and damp slow or late combustion, a task engine designers typically accomplish by feeding the engine an unnecessarily rich fuel mixture. Carbon fuels have become too expensive to be used partially as fire extinguishers, however much such mixtures simplify design for engineers and auto mechanics. Rich mixtures are necessary for starting and cold weather operation, but not leaning the mixture as much as possible the rest of the time is a waste of resources, especially in light Congressional calls for better CAFE [car average fleet economy] standards.
4. But the ecu [the on board computer system controlling combustion, braking, et cetera] can void all the above by detecting the leaner combustion [increased oxygen, or manifold pressure, in the exhaust system] and upping its fuel mixture imperatives to the carburetion/fuel injection system. And federal law makes disabling on board diagnostic components illegal. Whether capturing sensor signals and attenuating them back to the levels the system expects, to sustain better system performance, is a grey area. Apparently the trucking industry has explicit permission from the federal DOT for such experimental modifications. But for obvious reasons, the ordinary citizen in his domestic vehicle does not. Nevertheless, the driver who does not monitor his systems and limit its unnecessary negative responses is just spinning his own wheels.
5. So why have auto manufactures not installed such systems in new vehicles, or at least made them available as options?
1) they are complicated.
2) they require more maintenance than advertised.
3) they expose sloppy users to significant dangers, i.e. explosions, chemical burns from catalysts, economic losses from faulty information about installation and use, et cetera.

#116 of 133 mpg question? by dawsrt

Oct 07, 2008 (7:19 am)

Hi everybody, I'm new to this site so please bare with me. I recently purchased a new motor home on a Kodiak chassis with 6.6 duramax. I drove it home from Indiana to my home in Vermont averaging 8.3 mpg. Keep in mind that there is only 1,700 miles on it. I have asked several people how to get the best mpg and some tell me to drive on the conservative side and some tell me to drive it like I stole it. The idea behind that premiss i was told is to keep the engine as hot as possible so as to burn all fuel incoming to the engine thus increasing fuel economy. I will say that I had to do alot of mountain driving a few weeks ago, pushing it real hard and got 12.5 mpg on that outing. Is there anything to this theory or not I just don't know. Any advise would be appreciated.

#117 of 133 Re: mpg question? [dawsrt] by kcram HOST

Oct 07, 2008 (4:54 pm)

Replying to: dawsrt (Oct 07, 2008 7:19 am)
Your RV is certainly heavy enough to give the Dmax the work it wants. But since it's new and low on miles, you do want to keep the rpm (and heat) up until it's broken in and the rings have seated. This is particularly important since I imagine you won't be driving the RV every day.
 
Best practices during break-in:
- downshift on hills, both up and sown, this keeps the rpm up.
- shift the trans manually when possible, keeping the upshifts as late as possible (whether you have a stick or automatic)
- if you're on an open stretch of highway, downshift and stomp on the go pedal... this keeps your speed safe, but gives the engine more work to do
 
Once you've broken in, then you can drive conservatively.
 
kcram - Pickups Host

#118 of 133 by steelken

Jan 05, 2009 (1:40 pm)

I have a 2007 F250 6.0 ltre 2x4 crew cab at present I average 6.2 ltres per 100 klms .when my wife drives she gets 5.9 ltres /100 klms excellent to us. only added k&n filter system

#119 of 133 by steelken

Jan 06, 2009 (4:54 pm)

I have a 2007 crew 4x2 6.o .I use 6.1 litres for 100 klms ( 30+ to a canadian gallon) I installed a K&N filter system and improved from 26 mpg

#120 of 133 24 mpg possible with Dodge or Ford? by ingarage

Mar 22, 2009 (12:28 pm)

I don't know if it's possible to do what I want to do. I may be taking a job that requires a lot of freeway time and the company will buy my fuel but they want us to drive vehicles that get at least 24 mpg, typically cars. I want to use a 1 ton dually because I need one to pull a 23,000# gooseneck 4 or 5 weekends a year (on my time). My business driving will be at 65-70 mph, generally level freeway near sea level in California. I would buy a used truck, looking for the right gear ratio and tranny, and would make whatever mods necessary to the plumbing and programming, plus tonneau cover. Probably 2WD to save weight and height. 1st choice is Dodge mega cab short bed, then 6.0 or 7.3 Ford crew cab short bed. Has anybody achieved this average freeway economy? 5.9 Cummins likely more economical than the new engine? Is 3.54 a good ratio for this speed? Advice on engine mods? Do I have to have a stick? Do dual wheels kill me? I don't know if I'd want to tow that much with singles, even a few times a year.
 
I realize low numeric rear ends mean tougher towing with that big load. This would be at 55-60, so is there an automatic that will downshift to the right gear, or should I be looking at a manual? I'd go with an underdrive or overdrive if that give the most versatility. Again, I am willing to have an imperfect towing rig to get the high mpg unloaded.

#121 of 133 Re: 24 mpg possible with Dodge or Ford? [ingarage] by jim314

Mar 22, 2009 (1:47 pm)

Replying to: ingarage (Mar 22, 2009 12:28 pm)
You're dreaming that with mods and option choices you can get 24 mpg with a truck that can tow a 23,000 lb gooseneck.

#122 of 133 Re: 24 mpg possible with Dodge or Ford? [ingarage] by gagrice

Mar 22, 2009 (7:45 pm)

Replying to: ingarage (Mar 22, 2009 12:28 pm)
Just take the money for 24 MPG equivalent and pay the difference. I think 20 MPG is more realistic for a 1 Ton Dually.

#123 of 133 Re: 24 mpg possible with Dodge or Ford? [ingarage] by longtallsam

Apr 22, 2009 (5:19 pm)

Replying to: ingarage (Mar 22, 2009 12:28 pm)
It may be possible with an '06 or older Dodge Cummins. I had an '03 2500 2WD, and after getting broke in good, it was consistently getting 26-27 highway, running 75 mph. I then had an '06 2500 2 WD, and it got 23-24. Both of those had the auto transmission. I don't think the Fords get that kind of mileage.
 
I then traded for an '08, because I wanted 4 WD, and that was a big mistake! I had to replace the catastrophic converter and particulate filter at 17,000 miles, and have never gotten better than mpg.

Messages Page 13 of 14

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