How to Increase Mileage for a 2008 F250 Diesel Pickup

I don't know anything about this chip but "send me money and I'll double your gas mileage" sounds too good to be true.

Best course of action: Be very careful.

think about it. the function of the chip you have deals with timing and fuel injection. if changing these would yield such s gain don't you think during the same development of the enginethat Ford would have done the same thing?

It might help to know more about how you use your truck.

Mostly highway miles? City? or split?

How often are you pulling a trailer or hauling a significant load?

Is this a manual transmission? Have you made any modifications? What kind of tires?

This info isn't necessarily performance chip specific, but there might be some ways to reduce the amount you spend on diesel.

Also, you might find useful info in ecomodder.com and dieselnet.com.

Propane injection can increase MPG by 30%

'....Propane injection can increase MPG by 30%....'

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Sure, but how much Propane (at what cost) did it take to reduce the Diesel consumption my 30%?

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I have heard good things about propane injection improving diesel combustion and improving efficiency.

Yes there are chips or programmers available that allow you to increase performance- horsepower, increasing vehicle speed limit governors, changing trans shift points AND better fuel economy as well. But there is a tradeoff and that is in often the form of higher exhaust gas temperatures. These things typically change the injection timing values and similar computer controlled functions from factory preset values (which have been selected for emissions and average engine longevity reasons as well!).

As an example, my brother in-law had a 2005 2500 Duramax that had been completely reprogrammed, new intake & 4" exhaust- everything but a new turbo. It had over 500 Hp at the rear wheels & got close to 900 Km out of a tank- my (close to) stock 2002 gets a bit over 700 km under similar circumstances. The difference is he sold it after blowing a head gasket.

So what you have to consider is how much you want to spend and how long you want the engine to last. To get really good mileage you will also have to upgrade from the factory exhaust, it will make a difference if you tow etc. The best place to get advice for this is a diesel truck forum.

Note that these are also available for gas (Petrol for the Brits!) engines. They just don't see the same level of improvements.

I was advised that the exhausts would have to be made bigger if I used a chip.

What about compressed natural gas mixed with the diesel? Aren't those systems available now? I wonder what would happen if a chip and cng was added? The truck is used mostly to pull my small (20') travel trailer. I don't like to stay in motels. The tires are stock size. Of course, if I add a chip and then blow a head gasket, the extended warranty I purchased may be invalid. My brother used to drive an 18 wheeler cross country and he said that sometimes he would get 8 miles to the gallon. I guess the gearing is the difference.

Thanks for all the info,

Have some fun today,

PAPADOC

RMFR

CNG, LPG, Propane, all have about the same benefits, please see my earlier post with links #8

Preach on, brother!

GA from me.

Thank you!

I had a 1996 350 turbo diesel a few years back. It was tricked out with the chip, 4" exhaust, etc and I got around 12 mpg. I sold it because it was too big (crew cab), but it was powerful and satisfying to drive.

Realistically, you could double your mileage if you drove it half as much.

These chips rob Peter to pay Paul. So, you can expect less torque and power and possibly other long term side effects. Everything has its price and it has to be paid. There is no free lunch.

The best solution I can think of is:

1. Consider if you really need this truck. What is the purpose and when?
2. What is the impact with a smaller truck if you need a truck 100% of the time?
3. Can you buy a second economy vehicle for the driving that does not require a truck?

For me the answer is I can get away with a 2-seater car 99.999% of the time. I may need a truck 2 or 3 times a year, so owning a truck is not even close to a consideration.

If I needed a truck 20% of my drive time I could justify buying a beater truck and using it only when I needed it.

Your mileage may vary. You may just want a truck because you want a truck. That is okay, but you just need to be prepared to pay the cost of ownership.

Or, you may actually need a truck for business or whatever. Either way, you are going to have to live with all the perks and downsides to owning a truck. Fuel mileage is just one of those costs.

Where I live (rural Mississippi, most people have trucks. Here we have to haul building materials, go to the dump, go hunting, move furniture and do many things that require a truck. The truck here is the preferred means of transportation with the automobile second. It all depends on the part of the country you live in and the activities engaged in and I'm not even mentioning the use of trucks by tradesmen and building contractors. I'm retired, my son is in the Air Force, my daughter cleans houses and all my friends drive trucks as the principal mode of transportation. I can remember back when pickup trucks were dirt cheap compared to automobiles. Now they cost as much or more than an automobile. The public discovered that pickups were an economical vehicle to buy as long as appearance was not important. Detroit realized right quickly a market existed for PU's and now they are as fancy as autos. As you said, "there is no free lunch" and Detroit is making sure that doesn't happen.

AH, you wrote:

'....So, you can expect less torque and power and possibly other long term side effects. Everything has its price and it has to be paid. There is no free lunch.....'

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You are right that 'everything has its price' and that 'there is no free lunch'....but on this one, the tradeoff you have identified is not the correct one.

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Typically modifications such as aftermarket chips, disabling EGR, aftermarket intakes and exhausts; can provide both an increase in efficiency AND an increase in torque and power. .

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The real tradeoffs are typically increased production of oxides of nitrogen, increased noise, voiding of warranty, possibly not passing emissions inspection, and possibly shortening engine life.

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Most typical modifications for improving efficiency also increase available power and torque. I can think of very few that don't.

While every vehicle type is different, typically, when you alter the computer mapping for increased power and torque it does so at the expense of fuel economy.

Any 'expense of fuel economy', is almost certainly a result of driving in a manner which makes the increase in torque and power most apparent.

The efficiency typically increases as a result of increased in cylinder temperature/pressure and more complete burning. Driven under the same way undeer the same conditions, the chipped vehicle will usually get better mileage. It will also produce slightly less exhaust but with a higher percentage of oxides of nitrogen. Unfortunately I don't think much work has been done to see how much the reduced total emissions offset the increase in oxides of nitrogen.

Not really if you are just changing the engines fuel energy conversion process to favor producing mechanical power from the fuel energy instead of waste heat going into the cooling system and exhaust it's possible to pick up substantial mechanical HP and mileage numbers while actualy using less fuel not more.

The problem with emissions systems is just because theoretical models suggest that a type of engine and fuel can be x percent effect that does not mean it is tuned to be anywhere near that level in order to meet emissions numbers.

Unfortunately this detuning to favor emissions instead of mechanical efficiency can and often does take engines that could easily run at 30 - 35% mechanically efficient levels and puts them down well into the lower teens or worse mechanical efficiency percentages.

Ah. Those darned emissions.

Being the you have a 2008 F-250 your truck should have the twin turbo 6.4 liter diesel. I have a 2008 E-350 with the so called reject motor of the Ford powerstroke series. My E-350 gets an average of 18 MPG compaired to your 9 MPG with your 6.4...

The reason the 6.0 has such a bad reputation was Ford's BAD engineering of the emission system and the owners not keeping up with routine maintance of the emission system..

Now 2008 comes along and Ford has a better idea with it's new 6.4. They did reengineer the emission system that requires less owner maintance then the 6.0 and added a diesel particulate filter to keep the 6.4 within 2008 emissions standards.

Here is where your bad MPG comes in, when the engine control module senses the diesel particulate filter is getting clogged the engine control module starts dumping more fuel to the injectors to raise the exhaust gas temperature to burn off the collected particulate while wasting diesel fuel to do it...

Is there any way to change the emission system to get better mileage and still be within the law?

Thanks,

PAPADOC

RMFR

One option is to sell it and invest in a "shifty fifty" instead.

I purchased a 2003 7.3 used several years back and the vehicle would only get 11.3 MPG and I could not afford it. As it was under factory warranty I took it to the dealer and they claimed to give it a good going over changed two injectors and gave it back with no improvement. In desperation I took it to a well respected diesel shop 100 miles away and left it. These people were on the ball as I had used them before on another vehicle I had. They installed a EDGE Products tuner set it on the low setting and the results were 19.5. MPG with increase of 60 HP. Not that I needed the HP but it came with that tune. I had the vehicle two years and it ran perfectly all the time that I owned it. I do not know what the factory settings are or why some of them do not produce the economy but my experience with this company is 100% positive. There are many good companies just pick up a Diesel Magazine and check the ads. Call to see if there is a 100% satisfaction or money back warranty and get going.

Years ago I had an E350 van with the big diesel, before the PowerStroke came out. Added in an OverDrive to slow down the engine when I didn't need as much power. It had the aerodynamics of one brick on top of another but cruised down the highway at 22 MPG. www.gearvendors.com .

In a former occupation I was licensed to test and certify vehicles in the state of California. It has always bothered me that the emission standards are based on the percentage of emissions coming out of the tail pipe. Testing used to be performed only at idle. Now testing is performed at road speeds, but not under load (drive wheels spin, but they are not loaded.)

Standards should be written to control pollutants per mile rather than the current standards which do not consider fuel consumption.

For a pick up truck, you will notice a significant improvement in mileage if the bed is covered or if the tail gate is removed or just opened.

So what exact pollutants are they testing for and to what levels?

Also how do those levels compare to older vehicles or off road vehicles that do not have or require emissions systems?

The pollutants that are tested are: Hydrocarbons, Carbon Monoxide, Oxides of Nitrogen, particulates, etc. and soon, green house gasses.

The levels vary depending upon the age and category of the vehicle. There is a 250 page document called "The California Low-Emission Vehicle Regulations" which specifies the levels.

Off road vehicles are not exempt as they are addressed in the regulations. In reality, since these vehicles may not be registered, they are not tested for compliance every other year as required by the Department of Motor Vehicles when registering a road vehicle.

Vehicles manufactured before around 1957 or 1958 are exempt.

some pretty dry legal speak reading there.

From what I could pull out of it the emissions numbers stated most couldn't be met by any person who smokes or any form of external combustion such as a barbecue, wood burning fireplace, or fire in general man made or otherwise let alone be the least bit realistic for a IC engine.

To be honest I almost question the peoples knowledge of chemistry and physics that come up with those proposed numbers especially if they now want to go after CO2 emissions.

The only fix I know of to reduce CO2 output from a combustion process is to burn less fuel which is well known for being highly counter productive to emissions standards and engine redesigns/detuning in general that require us to burn more fuel to do go less distance or do less useful work.

Unless the measurements are based on "parts per specific volume" then the readings are not specific to the quantity of fuel consumed.

In the state I live in pollution tests are required on a regular basis. CO and unburned Hydrocarbons are measured and each vehicle has a limit of "X" parts per million. If the vehicle exceeds the limit it fails. It is not a question of volume of fuel, it a measurement of concentration in the exhaust.

Changes to the controls managing the engine, like disabling the pollution control equipment or replacing a "chip" will most likely cause the vehicle to fail and may violate state & federal law.

I wasn't the one implying that the measurement needed to be specific to the amount of fuel burned....that was your previous post.

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By the way, if only CO and unburned hydrocarbons are measaured then most chips would probably have no problem passing an emissions inspection.

My mention of CO and unburned hydrocarbons covered only part of the testing process in this state.

Someone interpreted my "volume" comment incorrectly.

I had my 2003 7.3 tested when I purchased it as it was mandatory and it passed, after I had the tuner installed about one year later it was tested in another province and it passed even better than the factory tune. Mileage never varied from the improvement and this was a dually with 4:10 gearing. Had I kept it I would have installed 3:70 gearing for better mileage as this would have dropped the 100-120 KM speeds to about 1750 RPM the sweet spot for torque and supposedly best mileage.

Being based on a PPM levels of the exhaust makes even less logical sense for making us burn more fuel to get lower numbers.

Whats keeping me from just using a high volume low pressure air pump (turbo charger) blowing clean air directly into my exhaust to further dilute the PPM members without actually changing mechanical efficiency of my engine?

The thing is if it all just a game of PPM ratios I can pump loads of air into the exhaust system after it leaves the engine for very little energy consumption opposed to burning lots of fuel to move more air through the engine itself in order to reduce the PPM ratios.

Chemical reaction formulas don't pull byproduct ratios of reactions out of thin air literally by tossing in irrelevant quantities of other molecular substances that were not part of and had nothing to do with the chemical reaction itself.

They are all based on X amount of mass of atoms and molecules changing into other configurations of same mass of atoms and molecules while either taking in or giving off energy in one form or another in the process.

The point is PPM ratios are completely arbitrary without a mass input to resulting mass output value related specifically to the molecular mass of fuel and air that changed molecular forms durring the reactions that created the specific mass of the end reaction byproducts.

Pumping air into the exhaust has been done for years, it helps to burn off unburned hydrocarbons.

Whether or not that is the case, it must be obvious that doing so would would render analysis based solely on PPM of tailpipe emissions completely useless..

Reasonable analysis would also consider information like volume of exhaust, fuel mass, and power delivered.

Generally, the problem isn't CO2 emissions so much as NOx etc.

These byproducts are formed in higher quantities as the peak cylinder temperatures increase. So by limiting the peak cylinder temperature (as well as adding on all those other wonderfull emissions control articles) they can reduce these sort of things.

Oh, by the way one of the easiest ways to limit PCT for diesels is offsetting the injection event timing, spacing the pulses etc.. Unfortunately, best efficiency dictates you derive MAXIMUM PCT as this also generally gives maximum cylinder pressure. So retarding it means that less ΔP is developed, and more heat energy goes out the tailpipe (even though EGT's may be less!). Yup, them greenies done shoot themselves in the foot.

IMHO- the BEST way to limit PCT with a diesel is to reduce charge air temp. Each degree drop on the incoming air is replicated on the EGT apparently. So you can optimize the control parameters for maximum ΔP, and lowering the overall temperature range over which the cylinder expansion takes place means less loss to the cooling system. So more power, better mileage & you're less likely to fritz a turbo pulling an overloaded trailer through the mountains. Intercoolers are the typical way to do this but I believe that is also supposed to be one of the big benefits of propane injection for diesels. Have you ever done any of that in your conversions?

So far I have yet to acquire a diesel pickup to do any propane boosting testing on.

The only diesels I have to play with are the three farm tractors and my little single cylinder 6.5 Hp Petter diesel I tweaked the pump on to run used oil in without having flow or injection lag issues due to the higher average viscosity of used motor oil Vs normal Diesel fuel.

I did acquire a Allis Chalmers industrial 6 cylinder (2900T series) last fall that I am planing to put in my other 99 F250 Super duty. So far the plans for that are to just put a higher boost turbo and intercooler on it and rework the pump to get it up into the low to mid 200 HP range at 2800 RPM over its stock 120 - 140 or so HP rating at 2200 RPM it has now.

I am curious to see how a slightly worked over 300 ci industrial inline six diesel does in comparison to my 6.8l v10 for both power and mileage. The two pickups are identical so it should be a fair comparison test bed.

'...IMHO- the BEST way to limit PCT with a diesel is to reduce charge air temp....'

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I think you will often see higher PCT when the charge air temp is lower since more O₂ is available in cylinder to react with the fuel.

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I suspect it is very dependent on things like load and speed.

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I would certainly like to have access to some decent data on this type of thing.

I had originally thought the same thing. Several years ago I read an article about it. What was pointed up was that most people incorrectly compare diesel engines to gasoline engines in this regard. As diesel engines are fuel throttled, additional oxygen as a result of the denser charge does not make much difference until you are hitting the "black smoke" point; until then the excess oxygen does encourage more complete combustion (leading to more power, economy & reduced HC & CO), but this is mostly noticed at part throttle, under load as you approach the stoichiometric balance. Until then the unreacted oxygen & extra air constituents simply absorb more of the heat created by the combustion process.It was debated as to whether the denser charge also reduced percentage loss to the cylinder surfaces, resulting in higher average pressures throughout the power stroke but that was a matter of opinion. So the net result was that you could process more BTU's more efficiently, without necessarily having a significant increase in peak temperature.

I don't remember where it was but I would imagine a Google search would turn up more info. What I can verify from experience is that a modern turbo diesel, compressing air next to a red hot turbine, with compressor inefficiency & normal ΔT from the compression itself can easily add 100+ degrees to the charge air when you are towing.

One thing which will improve economy, power, engine/injection pump longevity, and reduce smoke is to add JASCO FC rated two stroke oil to your diesel at the rate of 1:200 ie 350ml to 70litres of fuel.

search "adding two stroke oil to diesel" on the internet for more information.

All engines, whether diesel or gas, have the potential for better performance and mileage. As they leave the factory, they are in a "detuned" condition. It's the after market providers who can get the most from a "stock" engine. Sure there are some tradeoffs; usually economy for performance, but most engines can be improved to a point before tradeoffs enter the picture. You would think race cars were all about performance, but fuel consumption also enters the picture. One of the best ways to improve performance and fuel economy is by shedding weight. Tires also contribute to improvement. So when you are thinking of improving fuel economy and/or performance, many different angles must be examined.

Your brakes are dragging. Pick up the wheels and see if they turn by hand, you might have a stuck caliper. After you take it for an easy drive, put your hand on each wheel and see if one or more is hotter than the rest.

If you have a noncontact temperature reading device, and can see the calipers or discs check it that way. If you have limited slip differential you must pick up both wheels to check by hand.