better fuel economy - Diesel Forum

mt454casull · 03-26-2008, 12:03 AM

I recently bought a 2004 ford f350 4x4 extended cab with the 6.0. I have 285/75/R16 Toyo MT tires. Any how, when I first got it I made a round trip of about 500 miles with the truck. The truck was totally stock. I got 18.3 miles to the gallon and that was driving it at about 60 without stopping except 2 times. I drove the truck back a fourth to work a few times an got about 15 miles to the gallon. Mind you I drive the truck very nice. Like I don't just put the petal to the metal all the time. Well, I bought a K&N Cold air intake. And I have been told about how horrible this is and all, but I have run K&N on many other trucks and never had any problems, so from my standpoint I like them. I also installed a 4" Silverline exhaust from the turbo back with the cat delete. I know that is terrible and all to get rid of the cat, but I am sorry I don't really care. I am from Montana and I can run whatever exhaust I want on my truck. So I drove the truck today to the city and did about 35 or so miles of driving around town shopping with the wife and what not, lots of stop and go. The overall trip was 150 miles, and I got exactly 20 miles to the gallon after fueling up right before we got home. I was driving about 65 miles an hour, when I wasn't in town. I think that has got to be about an average of 3 miles to the gallon better. I am really happy about this, since now days diesel is over $4 a gallon. Any how after I did all the mods on the truck I was really worried that I had just pissed my money away from hearing everyone else's opinions. I was told that the stock intake is so good that you might as well leave it. It might be good, but I certainly know that the truck is certainly getting better air flow now, and if it is getting the air it wants it is going to run better. Any how also I had been told that removing the factory exhaust could also make the fuel economy go down. Well, you are all free to your own opinion, but I am very happy with my results. I think 20 miles to the gallon for a big truck like this is great.

PerryB · 03-26-2008, 12:22 AM

Your mileage is excellent. I wish mine did so well! As far as the K&N air filter goes, I'd try to find a blue media Donaldson to replace it with. The induction tube is probably an improvement, but the filter element itself is what I don't like. K&N's pass fine dust particles,plain and simple. When used in a hostile/dust environment you will pay the price. You'll notice the company makes lots of hype and hoopla about how well their filters flow,but nothing about how well they FILTER. If you keep it loaded with oil you may be OK, but you'll have a mess. Been there done that. Just my $.02

mt454casull · 03-26-2008, 12:27 AM

thanks for the advice about the K&N. I have been a little worried about the dirt thing.

mt454casull · 03-26-2008, 12:31 AM

hey where would you look for those blue air filters, I have not hird of them?

mt454casull · 03-26-2008, 12:35 AM

I know that I can get the donaldson for the factory air box, but do they make a donaldson filter cold air itnake style?

stroker76 · 03-26-2008, 09:48 AM

that is awesome mileage, Mine on the highway only got 15 mpg and I have only after market intake and a cat delete flow master exhaust

capterik · 03-26-2008, 02:17 PM

Quote:

Originally Posted by mt454casull

I recently bought a 2004 ford f350 4x4 extended cab with the 6.0. I have 285/75/R16 Toyo MT tires. Any how, when I first got it I made a round trip of about 500 miles with the truck. The truck was totally stock. I got 18.3 miles to the gallon and that was driving it at about 60 without stopping except 2 times. I drove the truck back a fourth to work a few times an got about 15 miles to the gallon. Mind you I drive the truck very nice. Like I don't just put the petal to the metal all the time. Well, I bought a K&N Cold air intake. And I have been told about how horrible this is and all, but I have run K&N on many other trucks and never had any problems, so from my standpoint I like them. I also installed a 4" Silverline exhaust from the turbo back with the cat delete. I know that is terrible and all to get rid of the cat, but I am sorry I don't really care. I am from Montana and I can run whatever exhaust I want on my truck. So I drove the truck today to the city and did about 35 or so miles of driving around town shopping with the wife and what not, lots of stop and go. The overall trip was 150 miles, and I got exactly 20 miles to the gallon after fueling up right before we got home. I was driving about 65 miles an hour, when I wasn't in town. I think that has got to be about an average of 3 miles to the gallon better. I am really happy about this, since now days diesel is over $4 a gallon. Any how after I did all the mods on the truck I was really worried that I had just pissed my money away from hearing everyone else's opinions. I was told that the stock intake is so good that you might as well leave it. It might be good, but I certainly know that the truck is certainly getting better air flow now, and if it is getting the air it wants it is going to run better. Any how also I had been told that removing the factory exhaust could also make the fuel economy go down. Well, you are all free to your own opinion, but I am very happy with my results. I think 20 miles to the gallon for a big truck like this is great.

Well if the K & N comment that you were refering to in another post was mine, I said I got worse mileage with it in my stock truck, and I did not know what it did with a new less restrictive exhaust. On top of that, how do you know it was the k & n that caused the better mileage, it could have been the new exhaust that is the reason, or a combo of the two. I personally have heard that the better exhaust gets better economy, but it all depends on how you drive with it. Nice mileage and good to know that combo is working for you.

bismic · 03-26-2008, 07:01 PM

Bottom line - good mileage and glad you are happy w/ what you have done.

Since you graciously said we were free to our opinions ................

Two problems have been documented with the K&N -
1. oil soaked filter can interfere w/ the MAP sensor over time, and
2. the filtration isn't as good as stock.
Neither of these items will cause problems quickly. Certainly a personal choice as to what to do w/ the info, but many folks on dyno's have not seen improvements w/ more air until you get bigger injectors, so why risk having problems.

I would think it would be interesting (and helpful to the forum members) if you could repeat the test w/ everything the same except put the stock air filter back on. Opinions may become data driven facts at that point.

6.0lpower · 03-26-2008, 07:14 PM

Nice to see someone else report decent mileage in their 6.0l. A while ago I posted my results and they are similar to yours. I often get 24 mpg, that is Canadian gallons remember, and I have done 26 as a personal best. I know that some people didn't believe my results but like you I drive a reasonable 100km or 62 mph and I am easy on the accelerator. My cold air intake is an AFE but I ran a K@N in my 97 with no problems. I use oil analysis to see if I am getting dirt in the engine and have not seen any numbers that alarm me. Unlike your experience however I left the cat in place on my exhaust, I also went to a 3" downpipe and then a 4" exhaust. I think that the 6.0l is a good engine with reasonable fuel economy and good power. Have fun with your truck.

bismic · 03-26-2008, 07:25 PM

I agree, great to see more good mileage posted (Canadian 22-24 apprx. equals US 20-22 - very impressive).

One question though - how does UOA show if the turbo is getting coated or eroded with air contaminants? Also, the 97 turbos did not have the VGT unison ring or as tight of tolerances. I am also running a '97 7.3 (which I also love). I am not nearly as concerned w/ my '97's "AFE Stage 2 ProGuard 7" intake because of these differences.

I certainly don't want to discount the good reports on mpg, it is just helpful to us forum folks w/ limited $$'s to spend on mods to know the specific benefits before buying. Many folks say the intake is way down on the list. The majority of folks say the exhaust is fairly high on the list.

BTW - I am averaging 17 mpg (US) now after updating the computer strategies. This is w/ NO long highway trips, and relatively few short trips also.

6.0lpower · 03-26-2008, 08:27 PM

Good question, Bismic. I don't think uoa will show if the turbo is getting coated but it will show if you are getting dirt in your engine. If you look at the uoa and see a high silica count that indicates dirt. The only way dirt can get in is through your air intake. That of course does not include higher numbers on new engines which may have silica in the oil do to manufacturing and gaskets. Finning CAT analysis shows my silica count to be 5 which is good. On my 97 with the K@N the silica numbers were usually between 5 and 10 depending on summer or winter and if I was spending a lot of time in the prairies. Dust.

Oil on the turbo or the sensor has not been a problem yet. I am careful not to over oil and I don't over clean.

mt454casull · 03-26-2008, 11:28 PM

Well, I will have to watch an see if I get too high of a silica count. My comment about the K&N was not toward one person impaticular, I have just seen many peope write things about the K&N not letting verry small particles of dust get buy. I will be honest here, I don't know a lot about diesel engines, but I am an aircraft mechanic, and do work on a lot of turbocharged aircraft. The airplanes I wourk on have an airfilter that is pretty much a piece of foam about an inch thick with a little oil on it. I can see that dust particles are getting past these filters when I take them off to replace them. What I would like to know, is if these verry small dust particles can really do that much damage. I don't really see any adverse affects, or turbos not lasting long at all due to these aircraft air filters. I also have no doubt that A K&N has got to be a better filter than these filters I am putting on aircraft. I am not saying that dirt is good for anything, but the engine in the first place has a lot of stuff like carbon and small ammounts of metals from your engine wear, which is more abrassive than a verry small amount of dust. Also think about a jet engine. They taxi arround sucking all kinds of dirt off of the runway unfiltered. These blades are spinning faster than turbo charger blades. Here is my 2 bits of openion. I change my oil every 3000 miles in all of my vehicles. You are gowing to get bad stuff in your oil one way or the other and the dirtier it gets the more engine wear you will see. I guess what I would really like to know is if these K&N filters can directly be linked to shorter turbo life or engine life? Again this is just my 2 cents and you all have the right to your own.

mt454casull · 03-26-2008, 11:31 PM

I am just starting to learn about all this diesel stuff, so feel free to set me straight, I won't be offended.

bismic · 03-27-2008, 04:38 AM

Quote:

Originally Posted by 6.0lpower

Good question, Bismic. I don't think uoa will show if the turbo is getting coated but it will show if you are getting dirt in your engine. If you look at the uoa and see a high silica count that indicates dirt. The only way dirt can get in is through your air intake. That of course does not include higher numbers on new engines which may have silica in the oil do to manufacturing and gaskets. Finning CAT analysis shows my silica count to be 5 which is good. On my 97 with the K@N the silica numbers were usually between 5 and 10 depending on summer or winter and if I was spending a lot of time in the prairies. Dust.

Oil on the turbo or the sensor has not been a problem yet. I am careful not to over oil and I don't over clean.

Thanks for the response 6.0Lpower. Terry Dyson (doing my oil analysis interpretation) has mentioned the silica numbers related to air intake. I am still trying to understand the path into the oil. Maybe from the turbo oil return system?

My virgin oil has Silicon at 6 ppm. My UOA is at 10 ppm (still slowly coming down for the reasons you mentioned).

capterik · 03-28-2008, 10:21 AM

Well, like I said in n earlier reply, not sure how much you can contribute to the filter or the exhaust. I made a post yesterday detailing my new exhaust and edge platinum juice with attitude. Went from 17.2 to 20mpg. I have stock air filter in right now. I am having a ram air hood being painted right now, and hopefully next week will install it with the air system for it and with the edge lcd, I should be able to see if the EGT's change one way or the other. If it makes things worse I will use the ram air to cool the engine compartment, and retry the K & N and S & B that I have or go back to stock. Thats the problem with doing more than one mod at a time. You never know which mod does what, but see the total result. I do plan on running my edge on stock for a ways to see the difference from economy mode.