3rd Gen Engine and Drivetrain -> 2007 and up 6.7 liter Engine and Drivetrain discussion only. PLEASE, NO HIGH PERFORMANCE DISCUSSION!

Increase Mileage 25%!!!

Thread Tools
 
Search this Thread
 
Old Feb 13, 2008 | 06:38 PM
  #46  
scootertrash35's Avatar
Registered User
 
Joined: Jun 2007
Posts: 500
Likes: 0
From: conroe tx
i won't use a fram anymore,my 5.9 sucked 2 of them apart,and a factory style(with the scotchbrite pad)up into the lid.i like the stp from autozone,their cheap and they have 3 glue strips across them to keep their shape.
Reply
Old Feb 14, 2008 | 04:28 PM
  #47  
Scotty's Avatar
Top's Younger Twin
 
Joined: Nov 2001
Posts: 3,743
Likes: 21
From: Thanks Don M!
I just returned. Logged a total of 3106 miles. Half of that empty. Calculated mpg was 16.2 but I did have a tail wind for about 3-4 hours of that. Thats an increase up from 14.8 last trip and it was colder this trip which usually equates to less mpg. I cruised at 70 MPH.
On the return the overhead was reading higher as well and I was hauling a taller and heavier 5th wheel. Calculated last trip was 7.7 and this trip after the last fill up was 9.2. The overhead was out by .7 mpg higher across the board. I cruised at 66 or 110 kilometers per hour...winds were actually a bit better in my favor for a change on the first day and then a nasty cross wind today. The truck seemed to run better and the only thing changed was the filter. A filter off of an 04.5-07 5.9 drops right in.

I really wasn't expecting this kind of difference but I sure will take it. I have no rational reason for this other then the factory original filter is just plain too restrictive.

Of course there will be folks out there arguing and debating this and the reasons for the improvements. However, when I log 10K miles a month and can net this kind of savings by putting a different filter in, consider it done. I do plan to do an oil analysis at 10K miles. I doubt there will be any glaring issues.

Other then that the truck ran pretty much the same. I do wish that I had an EGT gauge in place though. My guess is theres more cooler air, better combustion with maybe a bit more boost, which means lower egts...usually. I am going from experience here but like anything on these 6.7's it may not apply in the same way.

If I encounter any changes up or down on the next trip [plan to leave Monday] I will report.

A friend of mine has an aftermarket air intake that he claims has never netted an improvement in MPG. He intends to remove it and replace with the factory box and the 5.9 filter. I will let him report his results when he wants.

Scotty
p.s. there is such a thing as too much filter.
Reply
Old Feb 14, 2008 | 09:23 PM
  #48  
trt490's Avatar
Registered User
 
Joined: Feb 2005
Posts: 18
Likes: 0
From: Snohomish, washington
Thanks for the report on the trip and the filter, I'm wondering how the after market will improve mpg on a long trip, also do you have a auto,4.10 or 3.73, dually ,my 2008 shortbox 4x4 auto 3.73 gets 13 mpg in town, and 18 on the freeway,dont know what it gets towing ,only have a 1000 miles on her, and when I do tow it is only a toy hauler maybe 10,000 lbs loaded, we will be towing in a couple weeks I WILL REPORT THEN ,SEE YA
Reply
Old Feb 15, 2008 | 11:49 AM
  #49  
george colvin's Avatar
Registered User
 
Joined: Jan 2008
Posts: 7
Likes: 0
From: Carlsbad, CA
K&N Option

Try a K&N filter. Less resistance to airflow, while considerably stiffer to resist the increased flow.
Reply
Old Feb 15, 2008 | 01:45 PM
  #50  
Hounddog's Avatar
Registered User
 
Joined: Mar 2004
Posts: 4,463
Likes: 0
From: Ila georgia
K&N not much thouight of on these forums.Filtering abilitys are very questionable.
Reply
Old Feb 15, 2008 | 01:46 PM
  #51  
Spooler's Avatar
Registered User
 
Joined: Jan 2006
Posts: 5,902
Likes: 5
From: Claxton, GA
Originally Posted by george colvin
Try a K&N filter. Less resistance to airflow, while considerably stiffer to resist the increased flow.
No way on the K&N. It lets to much dirt pass. Plus, you will pull fibers out of the media and it will look like it has fuzz on it. Had one do that to me on my 5.9. Chunked it in the garbage.
Reply
Old Feb 16, 2008 | 11:47 AM
  #52  
Scotty's Avatar
Top's Younger Twin
 
Joined: Nov 2001
Posts: 3,743
Likes: 21
From: Thanks Don M!
Originally Posted by trt490
Thanks for the report on the trip and the filter, I'm wondering how the after market will improve mpg on a long trip, also do you have a auto,4.10 or 3.73, dually ,my 2008 shortbox 4x4 auto 3.73 gets 13 mpg in town, and 18 on the freeway,dont know what it gets towing ,only have a 1000 miles on her, and when I do tow it is only a toy hauler maybe 10,000 lbs loaded, we will be towing in a couple weeks I WILL REPORT THEN ,SEE YA
Truck is an auto Long bed mega cab dually 4x4 with 373's.
Hook up and tow. Sooner the better for a good break in.

Scotty
Reply
Old Feb 16, 2008 | 12:27 PM
  #53  
Cuminapart's Avatar
Registered User
 
Joined: Aug 2007
Posts: 105
Likes: 0
From: Alberta
Originally Posted by Scotty
Truck is an auto Long bed mega cab dually 4x4 with 373's.
Hook up and tow. Sooner the better for a good break in.

Scotty
Thats similar to what I'm seeing (2MPG) and our trucks are fairly similar, only I have the Mega cab(heavier slightly) Do you still have the silencer baffle in your intake hose? I have had mine out since new. Tire pressures are 60 front/ 50 rear. I also find the mileage to improve slightly with the E- brake on... not to sure about this though. Sweet spot seems like 113Kph(1650 RPM)
Reply
Old Feb 16, 2008 | 02:13 PM
  #54  
Scotty's Avatar
Top's Younger Twin
 
Joined: Nov 2001
Posts: 3,743
Likes: 21
From: Thanks Don M!
Originally Posted by Cuminapart
Thats similar to what I'm seeing (2MPG) and our trucks are fairly similar, only I have the Mega cab(heavier slightly) Do you still have the silencer baffle in your intake hose? I have had mine out since new. Tire pressures are 60 front/ 50 rear. I also find the mileage to improve slightly with the E- brake on... not to sure about this though. Sweet spot seems like 113Kph(1650 RPM)
Mine is a Mega Cab as well...stretched to a long bed so heavier yet but not by a great deal. I have not yet altered the turbo inlet hose or the ring. I will probably leave the ring in first when I replace the inlet hose and put a crankcase breather bottle on the PCV. All I can think about when the positive crankcase ventilation is at the turbo is that the suction at that point is going to draw fumes/oil mist quicker then it should. Then it goes straight into the turbo/intercooler/engine.

Oil analysis on these engines are showing high soot levels and because of the regen and egr, higher fuel contaminants in the oil. For some reason I think the manufacturer[s] [Cummins and Dodge] ran to the finish line without really working out these issues and its now at our expense...whoops I got off topic.
I think the Lab Rat thread is all about this.

Scotty
Reply
Old Feb 16, 2008 | 06:44 PM
  #55  
NSANE's Avatar
Registered User
 
Joined: Feb 2008
Posts: 71
Likes: 0
From: Concord, NC
I think the 6.7 air cleaner is thicker because of intake noise levels. Just my .02
Reply
Old Feb 16, 2008 | 11:37 PM
  #56  
Cuminapart's Avatar
Registered User
 
Joined: Aug 2007
Posts: 105
Likes: 0
From: Alberta
Well I guess I missed the long part of yor post you will definitely be a bit heavier! I would be satisfied with 16 mpg in town/ 19 highway if I could figure out how to do it. just need 2 more mpg to get there...(on top of the 1.5 to 2 Im getting with the filter deal)
Reply
Old Feb 17, 2008 | 11:20 AM
  #57  
STATELINE's Avatar
Registered User
 
Joined: Apr 2005
Posts: 366
Likes: 0
From: SW PA
Originally Posted by NSANE
I think the 6.7 air cleaner is thicker because of intake noise levels. Just my .02
this is what I was thinking, probably due to the built in exhaust brake, it makes a bit of intake back feed noise when it comes on
Reply
Old Feb 17, 2008 | 08:45 PM
  #58  
Scotty's Avatar
Top's Younger Twin
 
Joined: Nov 2001
Posts: 3,743
Likes: 21
From: Thanks Don M!
Theres very little if any difference in the sound level in the cab or outside with the 5.9 filter. I was expecting some kind of turbo whistle or growl from the e-brake but got none.

Scotty
Reply
Old Feb 18, 2008 | 01:24 PM
  #59  
Cuminapart's Avatar
Registered User
 
Joined: Aug 2007
Posts: 105
Likes: 0
From: Alberta
Scotty , if you pull the intake baffle , you will notice the whistle a bit more, but its not annoying like a second gen with the ring out and with an aftermarket intake. Avg 15.6 today on a 230km round trip, unloaded at 120 Kmh. ( seems to be sneaking up on 16+ ) lets see what an oil and filter change will do for it! Maybe I should take it in to have the O2 sensor recall done/ latest reflash....but I'm afraid to let them touch it!
Reply
Old Feb 18, 2008 | 02:00 PM
  #60  
GMScott's Avatar
Registered User
 
Joined: Dec 2002
Posts: 3,463
Likes: 0
From: Pottstown, PA
This is very interesting. I logged 330k miles in two years on my 04.5 using nothing but NAPA Gold air & fuel filters. Never had any problems with the power plant that could be related to the air filter I was using. If this can really improve m.p.g.'s I might just jump on the bandwagon here. So far, I have burned about 1,000 gals. more fuel getting to 100k miles on the 07.5 than I did with the 04.5 on it's 1st, 2nd or 3rd 100k miles. That's a BIG difference and a BIG hit on the old bottom line with the 07.5. If I can get back at least 1 m.p.g. I could recapture a decent amount of coin from the fuel man, almost $3,000.00 at $3.10/gal.
Reply



All times are GMT -5. The time now is 04:02 AM.