Good F350 fuel economy?

[oil pan 4]

Loose the belt driven fan and replace it with an electric and pick up another 2mpg highway.

[RustyLugNut]

Originally Posted by TheGrimMechanic

No need to be confused. Deleting the EGR and AIS will improve your fuel mileage. On modern vehicles, the use of EGR is because manufacturers did a cost benefit analysis and would rather use a $25 valve to control NOX instead of a $300 3-way catalyst.

AIS was used long before O2 sensors came to be and is the cheap an easy way to meet EPA rules. AIS is another useless technology where accounting prevailed over engineering. Wideband sensor technology has made AIS obsolete for a long time.

The EGR on your vehicle has a sensor on it that detects the position of the valve. I agree with you that coking of the EGR is the most likely culprit, but there is also the possibility that sensor is bad or an issue with the connector or wiring. There is a way to trick the ECM into thinking the EGR is in place and functioning by chopping off the connector and placing some resistors in its place. I know this trick works on OBDI Fords (pre 1996 EEC-IV) and on some later OBDII (EEC-IV only. Not EEC-V). I'll dig up the diagram and post it later. You would still need to make sure flow through the EGR is blocked completely. If it leaks at all during idle, you'll have issues with idle quality, rpm, hard starting, etc.

I've read a lot about EGR theory and all of the arguments for/against it. I've read a bunch of b.s. about theoretical gains in reduced pumping loss, thermodynamic improvements (?), and improved combustion and I'm pretty sure those theories don't mean anything to 99.9% of the vehicles that have an EGR. (BTW, my wife's 1999 Jeep Cherokee w/4.0 didn't have one from the factory). The truth is, EGR is only used for ONE reason: to reduce NOX (oxides of nitrogen) in the exhaust. NOX emissions are very short lived in the atmosphere and eventually are reduced to N2 and free oxygen. The problem with NOX is its decay product is nitric acid. NOX and nitric acid are also caused by lightning strikes. Nitric acid breaks down quickly in the atmosphere also. The main reason NOX is considered a pollutant is in large enough concentrations in the atmosphere it will cause the reddish brown haze you see in areas that have heavy air pollution because of the presence of nitrogen dioxide (wikipedia(dot)org/wiki/Nitrogen_dioxide). NOX is created in an internal combustion by the presence of oxygen and nitrogen together under high pressure and high temperature. The higher the compression ration and the higher the combustion temperature, the higher the NOX content of the exhaust. NOX, as a percentage of the exhaust gas varies depending on a/f ratio and load and ranges from nearly 0 to about 2500ppm (0.0025%) under peak load at 16:1 a/f ratio. You can read about some of the (b.s.) theoretical gains with EGR here: wikipedia(dot)org/wiki/Exhaust_gas_recirculation.

I don't get the logic of using EGR if it's going to cause my fuel consumption to go up. I'm not against emissions controls on my vehicle but if they are so poorly engineered just to satisfy some disconnected political machine, that opinion changes. EGR almost killed the on-road diesel market because of the technical problems of making it work well enough to satisfy the EPA. Sadly, the 'fix' for EGR's horrible reputation for unreliability and reduced performance was the introduction of 'Diesel Exhaust Fluid' and the burden forced on the consumer of having to periodically fill a tank on your new diesel powered vehicle with piss. I could go on and on about some of the stupidity of some of the garbage you are forced to pay for when you but a car (purposely injecting and burning fuel in the exhaust do 'regenerate' diesel PDF's???) but I would be hijacking my own thread.

Modern vehicle systems 20 years advanced of what is found on your truck are beginning to use EGR to grab the few percent efficiency gains found in the so called "b.s. theory". And, you mix diesel theory with spark ignition operation. They are two different stories.

And the pollution mechanism for NOx also includes solar activation of NOx to Ozone - a far more long lived pollutant at ground level. That is the brown haze seen in valleys like Los Angeles and Denver. Even when not visible, the concentrations are elevated near any metropolis.

But, you are right, these topics are very broad and beyond the scope of this thread.

[TheGrimMechanic]

Originally Posted by RustyLugNut

Modern vehicle systems 20 years advanced of what is found on your truck are beginning to use EGR to grab the few percent efficiency gains found in the so called "b.s. theory". And, you mix diesel theory with spark ignition operation. They are two different stories.

And the pollution mechanism for NOx also includes solar activation of NOx to Ozone - a far more long lived pollutant at ground level. That is the brown haze seen in valleys like Los Angeles and Denver. Even when not visible, the concentrations are elevated near any metropolis.

But, you are right, these topics are very broad and beyond the scope of this thread.

Agreed. I guess my point was that in 1997, the technology was available (and had been for 10 years) to manufacture a vehicle that didn't need an EGR or AIS to pass federal emissions standards, especially for a heavy-duty vehicle (which had much less stringent standards than passenger vehicles at the time). EGR and AIS are throwbacks to the early 1970's when the big 3 were struggling to meet the requirements of the Clean Air Act and the newly created EPA. EGR was never introduced or intended to help fuel economy and any theoretical gains in the lab are irrelevant and insignificant in the real world. I also understand that the economics of manufacturing plays a big part here. Why spend the money on more advanced means on controlling emissions in 1997? Gas was around $1 a gallon and most consumers that were contemplating the purchase of a one-ton pickup most likely had fuel economy low on their list of priorities.

The comparison with what has happened with Diesel technology was just to demonstrate the economics of manufacturing something that is regulated by an institution that is so far detached from the real world (remember when the EPA wanted to regulate dust produced from dirt roads? And CO2 is now considered a pollutant.) that the manufacturers are forced to engineer technology into vehicles for emissions regulations that have nothing but negative impacts on fuel economy (the EPA's standard of 'grams per mile' is biased towards smaller cars and engines).

It's been a while since I took any college level chemistry but I'm pretty sure the 'brown cloud' is from NO2 (nitrogen dioxide). I DO remember some lab experiments with nitric acid that went very wrong and copious clouds of acrid red/brown smoke being produced. Not sure what the mechanism of reaction between NOX and ozone (O3) is but I know there are reactions between HC (unburned hydrocarbons) and ozone. BTW, ozone is not something found in internal combustion engine exhaust. Ground level ozone is mainly produced by the reaction of VOC's in the atmosphere in the presence of ultraviolet light. It is also produced by lightning and the simple reaction of UV light on oxygen.

But before I drift too far off topic, the goal with my old F350 is to match the fuel economy of my friends 2014 EcoBoost F150. I may not be able to get to 24mpg but I bet I can get close. And spend a lot less than $42,000 to do it.

Maybe there needs to be a new thread on what the impacts of emissions control technology and how to make improvements to those systems while improving fuel economy at the same time.

[RustyLugNut]

Here is a link to the EPA that sketches out the importance of NOx reduction as the interaction of VOCs, NOx and sunlight result in large levels of ground level ozone.

Frequent Questions | Ground-level Ozone Standards Designations | US EPA

Your point about economics being a great part of the equation should hint to readers that early adopted emissions technology is not anywhere near being optimal in attacking the problem. And, like any technology, there are growing pains.

The officials in place at the EPA are not entirely out of step with the common man. They do have open forums to discuss possible changes and laws. I know, I have been part of some of those discussions in the past. I agree with you that CO2 being listed as a "pollutant" is an undue burden to industry, but I and others got to have our say in the matter. The problem was, the scientist and engineers such as myself, were far outnumbered by Gaia Greenies. I had brought out my cousins to voice their needs as they own trucking companies, but they were far too few. The argument that the life of the oceans and the planting of forests was of greatest importance in buffering and absorbing any increases in CO2 was seen as outside the authority of the EPA so, they control what is in their sphere of influence.

Emissions aside, what you are doing with your truck to reach your goal of 24 mpg is laudable and important as pickups make up a large percentage of some communities. Once you have exhausted the easy engine modifications, you can peruse the aerodynamic possibilities. That opens up a world of gains as our trucks come factory equipped with horrid coefficients of drag.

[oil pan 4]

" Ozone - a far more long lived pollutant at ground level."

The half life of ozone at ground level is some where around 90 minutes.

[RustyLugNut]

Originally Posted by oil pan 4

" Ozone - a far more long lived pollutant at ground level."

The half life of ozone at ground level is some where around 90 minutes.

. . . I would like to see your basis for that conclusion.

The mechanism for ozone removal from ground level smog itself results in other irritating and damaging compounds. If the VOCs have aldehydes , these can start the conversion of ozone, but the resultant peroxyacl's are powerful irritants at parts per BILLION concentrations. The ultraviolet light band also causes the interaction of water and ozone leading to the breakup of ozone, but this also results in more peroxyacl production. Either way, the result is a product that is as damaging, if not more so, than the ozone itself. Yes, it eventually passes out of the air and into our rain water in dissolved nitrate forms, but now you are adding to the whole problem of over use of nitrate fertilizers. Add in the production of nitric acid from the direct removal of NOx by moisture and none of this is a pretty picture.

During the Bejing Olympics, transportation and industry was curtailed to reduce the heavy smog during the games. Acceptable reduction of Ozone and irritating resultants took three weeks.

So, even though ozone is not "long lived" in the sense of CO2, it and it's resultants, are very damaging to living tissue for the hours, days and weeks it can linger.

[RustyLugNut]

Originally Posted by oil pan 4

" Ozone - a far more long lived pollutant at ground level."

The half life of ozone at ground level is some where around 90 minutes.

My statement could be misleading to the reader. I would truly like to see a report or study making light of a 90 minute loiter time for ozone at ground level.

[Christ]

Stopping the AIP from spinning is the only viable fuel saving option. Plugging the holes does nothing but cause it to fight itself until it grenades eventually because it's constantly pushing against a dead wall and building internal pressure while the engine is running.

It probably would have been easier instead of changing all that stuff to just get yourself an idler pulley to replace the pump. You can also remove the internals of the pumps on some models, and that just leaves a couple bearings and a shaft to spin inside the housing. Still eats a little power, but it's better than pushing useless air. You can retune the EFI system to keep the cat active easily enough, too.

[oil pan 4]

Originally Posted by RustyLugNut

. . . I would like to see your basis for that conclusion.

Wikipedia or a google search.

[TheGrimMechanic]

Originally Posted by Christ

Stopping the AIP from spinning is the only viable fuel saving option. Plugging the holes does nothing but cause it to fight itself until it grenades eventually because it's constantly pushing against a dead wall and building internal pressure while the engine is running.

It probably would have been easier instead of changing all that stuff to just get yourself an idler pulley to replace the pump. You can also remove the internals of the pumps on some models, and that just leaves a couple bearings and a shaft to spin inside the housing. Still eats a little power, but it's better than pushing useless air. You can retune the EFI system to keep the cat active easily enough, too.

The parts I needed were on hand. I had them from a Bronco I had sold. As far as I know, there weren't any aftermarket AIS pump delete kits (idler conversions, etc.) that would work on my application.

The AIS pumps can be gutted quite easily. Pop the end plate off and remove the vanes and it becomes an idler. You still have to block off the hoses though. The exhaust pulses will cause some air to draft through the pump if you don't.

Even when the pump is functional, if it's not moving any air, it's consuming very little power. Because it's a positive displacement pump (and only compressing air to a very low pressure), when the flow path is blocked, any energy expended to compress the air inside the pump is released back to the engine once it has completed it's cycle through the vanes. Same physics GM relies on with their active fuel management V-8 that disable 2 or 4 cylinders (by closing the valves) during cruise. I've done the wood-plug-in-the-hoses trick before and it doesn't seem to affect the life of the pump.