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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 12 of 14

#104 of 133 Re: 4x2 vs. 4x4 and F250 vs. F350 3.73 rear end [firewalkerjohn] by dakotahawk

Jun 16, 2008 (4:35 pm)

Replying to: firewalkerjohn (Feb 21, 2008 10:35 am)
I have the Ford 2008 F250 Lariat Crew Cab 4X4 short bed with the 6.4 Diesel. I've owned it for about 3 months and have 7500 miles on it. The new diesel engine/exhaust is programmed by the factory to go into a "soot burn-off" mode whenever the exhaust soot collector starts loading up. On my truck, I've noticed the burn-off happens about every 300 miles. During the burn-off period (usually about 15 miles of hiway driving) the MPG will drop down to about 12mpg. After the burn off period is complete, the MPG pops right back up to its normal value. For my F250, that's about 18mpg on the hwy at 65mph.
 
My Ford dealership was unable to explain the 12mpg when I asked them about it, so I had to do some investigation to figure out what was going on.
 
As for the fuel mileage trend while the engine is breaking in, I've kept pretty good numbers on my mileage, and 90% of my miles are commuting between Arlington and Seattle - a 100 mile round trip at freeway speeds. When new, my truck got about 14mpg. Now, with 7500 miles, I'm getting about 18mpg. This drops to about 15mpg when I'm tooling around town. I expect that mileage will continue to improve another MPG or two as the engine breaks in...
 
As a comparison, I traded in a gas 5.4 Triton 2005 F-150 that was getting about 16.5mpg doing the same type of driving. Doing the math, it costs me 27cents/mile to drive my diesel F-250. It cost me 25.5 cents/mile to drive my gas F-150.
 
Am I happy with my diesel performance? Yep! Still trying to justify a chip. If I could find one that has proven increase in MPG without playing with the fuel injectors, I would be interested. I'm pretty sure that the only way to improve gas mileage is to tighten up the shift pattern.

#105 of 133 Why use Fuel?When you can run your car with water by jonbyrd

Jun 23, 2008 (11:30 pm)

Hey..people..have you ever heard of running a car on water.?
 
This is true,Why should we bother thinking about how to increase the mileage of the car using diesel.Even if we can increase the mileage its is still costly for us ,As the prices of crude oil are increasing day by day.So we should think of making a few alterations to the engine.We can run the car by the electrolysis of water producing Hydroxy gas.This is what called as HHO fuel.Lets think of it once.I have also seen some useful information in the site http://waterfuelkit.net.
 
I have given this idea because I have seen some of the people in the above posts saying that Its costing them a lot at a very low mileage and even the mechanics are charging a large amount of money.
 
I'm expecting a great milage at low cost using the HHO fuel
I hope you get what am saying.

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

Jun 24, 2008 (5:10 pm)

Replying to: trendom (May 21, 2005 7:42 pm)
Hello Everyone,
 
   I just joined this website after first researching hybrid cars etc. then fuel cell vehicles, and came across a site that said water could be used for fuel. My husband and I have a 2006 350 Ford Super Duty outfitted "to pull a house" bought with the intention of pulling a really big fifth wheel now used to pull a horse trailer and bought when diesel was "cheaper" than gas. Our other vehicle is a 2002 little Ford T-Bird and that is not fuel efficient. Our truck gets 14.9 miles per diesel gallon even not pulling. Any thoughts on this??????????????
 
Kathleen

#107 of 133 Re: How to get better fuel economy w/your diesel [ladykathleen] by jim314

Jun 24, 2008 (5:40 pm)

Replying to: ladykathleen (Jun 24, 2008 5:10 pm)
The water fuel claims are bogus, and the sites that promote it are a scam. Water contains no net fuel value. It requires more energy to electrolyze water to split it into hydrogen and oxygen than you could gain in hp when the hydrogen is fed into the hydrocarbon fuel stream.

#108 of 133 Re: How to get better fuel economy w/your diesel [jim314] by ladykathleen

Jun 24, 2008 (7:10 pm)

Replying to: jim314 (Jun 24, 2008 5:40 pm)
Hello Jim314,
 
    You have of course converted a diesel or other vehicle to using water??????????????? The conversion "kits" seem plasible. They are inexpensive so who out there has actually done the conversion and what are the results????????????????

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

Jun 25, 2008 (12:16 am)

Replying to: ladykathleen (Jun 24, 2008 7:10 pm)
In my opinium injecting water into a diesel is a big mistake and the repairs could be very expensive. A good web site to go to would be www.unitednuclear.com, then to their research and development site then hydrogen fuel info. These guys have been working on a hydrogen fuel conversion kit and hydrogen generator for quite some time. per them diesel will not run on hydrogen.

#110 of 133 Re: How to get better fuel economy w/your diesel [ladykathleen] by jim314

Jun 25, 2008 (5:47 am)

Replying to: ladykathleen (Jun 24, 2008 7:10 pm)
One has to be properly skeptical of all engine add-ons which are claimed to increase fuel efficiency. In the specific case of the electrolysis units which produce a miniscule amount of hydrogen and oxygen gas, there is no generally recognized scientific or engineering theory whereby they could do what they are claimed to do.
 
If they really did work as claimed, then they would be available from the vehicle/engine manufacturers, at least as an option. The purveyors of these devices are not bound by an ethics policy to conduct accurate and unbiased studies showing that they really do work. They cite unreliable anecdotal accounts as evidence that these devices work.
 

#111 of 133 Re: How to get better fuel economy w/your diesel [ladykathleen] by jim314

Jul 04, 2008 (6:14 pm)

Replying to: ladykathleen (Jun 24, 2008 7:10 pm)
The hydrogen enrichment devices currently available produce a miniuscule flow of molecular hydrogen and molecular oxygen, but the purveyors are claiming big benefits without any research to back it up. They cite research done at the US gov't Idaho National Laboratory, but that research does not support the claims of any benefit from extremely low levels of hydrogen enrichment.
 
For example, one company is currently selling their brand of hydrogen enrichment device for installation on large diesel trucks (over-the-road tractor-trailers, I assume) and diesel school buses. The unit is an electrolysis unit which sells for $7800 plus installation charge of $200, so $8000 installed! The company reports that the unit consumes two liters (2 L) of water per 10,000 to 12,000 miles! 2L of water weighs 2000 g, water is 11.1% hydrogen so this 2L would yield 222 g of molecular hydrogen (H2) over that 10,000 miles!
 
What is the mpg of a large diesel tractor-trailer? 8 mpg? 4 mpg?
 
Let's say 6 mpg. At that rate over 10,000 mi it consumes 10,000mi / 6 mpg = 1667 gal of diesel fuel. 1667 galUS is 6309 L times the density of diesel fuel, 850 g/L = 5,360,000 g of diesel fuel over 10,000 miles.
 
So the added molecular hydrogen as a percent by weight of the diesel fuel = 100% x 222 g / 5,360,000 g = 0.0041 %.
 
Such a low level of hydrogen enrichment has not been shown in properly controlled trials to have any beneficial effect. This is 1/100th to 1/1000th of the minimum amount of hydrogen that has been studied in hydrogen enrichment experiments. See http://en.wikipedia.org/wiki/Talk:Hydrogen_fuel_enhancement
 
I think it is money not well spent for some struggling shipping company or independent operator to be paying this much money for something which has not been tested in well controlled trials. The FTC should investigate these claims.

#112 of 133 Re: Fuel mileage chips? [ipokebadgers] by cot

Jul 08, 2008 (3:31 pm)

Replying to: ipokebadgers (May 23, 2008 12:14 pm)
What gears did you get the 07 GMC??? My 2002 7.3L Lariat was also stolen two weeks ago.

#113 of 133 Re: overdrive [mullins87] by joe183

Jul 17, 2008 (12:05 am)

Replying to: mullins87 (Aug 04, 2005 5:33 pm)
I have an '06 with 3.73's and the 6 speed manual. I was disappointed as well the first time I drove it finding such high RPM at highway speed. I had traded an '02. It had 3.55's and the NV 5600 tranny. The newer ones have the Getrag tranny. The difference is not only the lower geared rears but also the fact that the overdrive ratio in the NV 5600 was .73 and it is .79 in the Getrag. I felt I had no choice but to go to the Gear Vendors overdrive unit. I installed it in my garage with a buddy in about 5 hours. You will have to get the rear driveline shortened and a different yolk welded onto it.
 
I still had the stock tires and at 70 mph I was turning 1800 RPM. I drove from Billings,Mt to Bismarck, ND at about 67mph (1700 RPM) and got 20.3 mpg. I definitely improved my mileage. Since then I have installed a Lorenz 2 inch levelling kit in front and went with 35 inch tires. Also a Ranchhand bumper. Now at 70 I am at 1600 RPM and my mileage is about 15 mpg. I have installed lockouts and only noticed marginal improvement. Between the lift and the heavy non-aerodynamic bumper and, most of all, the larger tires, I think my mileage has taken the hit. Bottom line is that you will improve your mileage with the Gear Vendors unit but stay with the stock tires or only a wee bit larger. The other option would be for me to run in 5th gear overdrive at about 60 (1700 RPM). In that case the torque multiplication is signifigantly larger than in 6th overdrive and my mileage would likely improve. I just don't have the patience.
 
Lastly, I drove over the road for 10 years. Cats, Cummins, Detroits. You will notice that the peak torque on the Dodge Cummins is generally around 1600 RPM. That is where you will get the best mileage. The idea would be to run a slower speed at that RPM which is entirely possible with the overdrive unit. I wouldn't agree that one needs to "keep the revs up" to run one of these engines.

Messages Page 12 of 14

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