Mileage gains

[KLauber]

After removing some parts that interfered in the intake and exhaust side of the engine I have some mileage gains to report. Driving from Greenville SC to Odessa, FL over interstate and 2-lane roads I recorded 16. 2MPG vs the normal 14MPG prior to modifications. AVG speed was 65 MPH. The trip included about 25 mins of stop n go travel in accident and construction zones and a stop in Ocala to replace a clogged fuel filter. Trip length was 573 miles.



Coming back to Greenville, I stayed on the backroads for the most part except for about 45 miles on I-75. No delays were observed and I recorded 19. 3 MPG over 562 miles. AVG speed was under 60 MPH. I probably would have gotten better mileage had I stayed on I-75 and then I-85 and avoided the start-stops in all those little towns.



Deleting those unwanted parts gives instant financial rewards!



Ken



PS, this was measured from tank-fill to tank-fill using the first click auto-stop on the delivery hose. The overhead display is not very accurate.

 

[crispyboy]

Interesting mileage results you are getting. I have often wondered if it is worth the hassle of deleting things from the engine.
My fully stock truck has been getting 17. 5 all this summer of mostly my 17 mile drive back and forth to work. I have hit 18 mpg on the expressway. I towed my camper last weekend 350 miles round trip and got 13. 03 mpg.
It seems like I am about 1. 5 mpg less than you truck. I have 27,500 miles on the truck. Mileage improvements for me started after 20k miles. The truck has 3. 73 gears.

 

[KLauber]

There are so many variables that can come into play. But the difference in MPG is a clear winner for me anyway. Might I suggest you unplug the EGR for a tankful and see what you get. Ignore the CEL, if you check the DTC, it will probably say low voltage EGR control circuit. A free mod and one that has instant benefits. Post the results if you do it.

Cheers,
Ken

 

[KLauber]

The EVIC lies!

Interesting mileage results you are getting. I have often wondered if it is worth the hassle of deleting things from the engine.

My fully stock truck has been getting 17. 5 all this summer of mostly my 17 mile drive back and forth to work. I have hit 18 mpg on the expressway. I towed my camper last weekend 350 miles round trip and got 13. 03 mpg.

It seems like I am about 1. 5 mpg less than you truck. I have 27,500 miles on the truck. Mileage improvements for me started after 20k miles. The truck has 3. 73 gears.

The EVIC mpg numbers are usually 10 to 20% higher than what you calculate from tankful to tankful. In my latest trip, the EVIC said 21. 6 and I calculated 19. 3 based on actual fuel consumed.



Ken

 

[KLauber]

Filled the tank in Hendersonville NC, drove back to Greenville SC and used 1. 8 gallons in 42 miles for 23 MPG and the EVIC said 22. The 1100 foot drop in elevation plays a small part since it occurs in a very short distance. It is relaxing to coast down a 6% grade in neutral though.

Ken

 

[wjpatton]

I've had the EGR unplugged for 2 fuel refills (always visible in the neck for consistancy). Been driving the same 52 mile loop, again for consistancy. Showing about a 1. 5 mpg gain. Hand calulated always, never believed the overhead!!

 

[KLauber]

I've had the EGR unplugged for 2 fuel refills (always visible in the neck for consistancy). Been driving the same 52 mile loop, again for consistancy. Showing about a 1. 5 mpg gain. Hand calulated always, never believed the overhead!!

WJ,



What are your truck specs? I believe you'll see the most gains in highway driving on gentle terrain (of course). We have very hilly terrain around Greenville with very steep drops between hill tops.



Ken

 

[wjpatton]

Sorry 'bout that!



2007. 5 3500 DRW 6 speed auto w/3. 73 gears quad cab. All stock except for 4" cat-back exhaust.



Mr. Bill

 

[SOLER]

I'm wondering how you guys are getting better than 12 mpg with the same truck I have??? I'm lucky to get 10-12. I used to love driving my truck, but now I absolutely never drive it unless I'm getting lumber or pulling my trailer.



You say you're getting better than 15 mpg stock. Is there a re-flash I should go get? Before I do anything aftermarket or pulling anything off or unplugging, there must be something I can do to get better gains with stock config. Now, granted, the truck only has 6-7k on the ticker. It's a double edged sword... it should get better with more miles, but can't afford to drive it to get more miles on it :=(

 

[wjpatton]

I don't drive mine in town, for all the reasons you've mentioned... Only pulling the 5er except for the previously mentioned freeway loop I drive once a week just to stretch it's legs... The mileage WILL get better with more miles, mine sucked initially, too. It is a BIG truck, with big HP, it will not get good stop and go mileage, physics, pure and simple. I drive using the manual shift mode, light foot and keep the revs up when I am in traffic, and never get into 6th until on the freeway. It seems to help. . Since the last reflash, the oil change intervals seem to have increased, but then again, very little use except pulling... . Hope this helps... .

 

[Jim W]

I'm wondering how you guys are getting better than 12 mpg with the same truck I have??? I'm lucky to get 10-12. I used to love driving my truck, but now I absolutely never drive it unless I'm getting lumber or pulling my trailer.



You say you're getting better than 15 mpg stock. Is there a re-flash I should go get? Before I do anything aftermarket or pulling anything off or unplugging, there must be something I can do to get better gains with stock config. Now, granted, the truck only has 6-7k on the ticker. It's a double edged sword... it should get better with more miles, but can't afford to drive it to get more miles on it :=(

I do not have a 4th gen truck, but I do have an early 08, 6. 7L, Mega Cab built in Nov 07. When I was stock I could only get 10 to 11 MPG in town and 14 MPG at best on the highway. When pulling my 5er I could only average 11 MPG. This was way better than my 2001, 6. 0L, Chevy got when pulling the 5er so I was happy.

Then I started to read the forum boards and try all sort of things. The first thing I did was un-plugged my EGR and I started to get between 12 and 13 MPG in town and 16 MPG on the highway. Towing I got around 11 to 13 MPG on long trips.

In Aug of 09, I installed a Smarty and did the deletes to the DPF and EGR. I am now seeing a steady 13 to 15 MPG in town and 19 MPG on the highway without the 5er attached. When towing I am seeing a steady 12 to 14 MPG towing on long tows.

I am will to void the factory warranty and become my own warranty station, since the only warranty issues I had were with the emission equipment on the truck.

I also have 4 years of data on excel spread sheets to back up my statements. All of my mileage is hand calculated and I record down to the tenths. I also do a yearly MPG average for the truck.

Jim W.

 

[Whiteranch04]

I have a 3500 4x4 six speed single rear wheel, smarty 67me, turbo back 5 inch, egr delete, and was getting about 13 at 70 mph, after i took off all of the junk, deleted, run the smarty on lowest setting due to clutch slippinglol, i get 19 to 20 on the overhead at 70 or 80 makes no difference, the truck is a pleasure to drive and cant wait to get the new dual Valair tow clutch in it My question is how much more milage could i get if I install the dynatract free wheeling hub kit?? I am so sick of it wearing out the front driveshaft ever 50k miles its not funny, I figure its about 2 or 3 more miles per gallon and saving the stranding from failed unit bearings or front driveshaft going out on interstate?? Anybody got the fulltime hub delete installed with about the same aftermarket stuff i have, how much should i expect?? THanks, i love to get 22 or 23 mph honestly???

 

[DennyDay]

I have a 3500 4x4 six speed single rear wheel, smarty 67me, turbo back 5 inch, egr delete, and was getting about 13 at 70 mph, after i took off all of the junk, deleted, run the smarty on lowest setting due to clutch slippinglol, i get 19 to 20 on the overhead at 70 or 80 makes no difference, the truck is a pleasure to drive and cant wait to get the new dual Valair tow clutch in it My question is how much more milage could i get if I install the dynatract free wheeling hub kit?? I am so sick of it wearing out the front driveshaft ever 50k miles its not funny, I figure its about 2 or 3 more miles per gallon and saving the stranding from failed unit bearings or front driveshaft going out on interstate?? Anybody got the fulltime hub delete installed with about the same aftermarket stuff i have, how much should i expect?? THanks, i love to get 22 or 23 mph honestly???

I went with the Spynatec free wheeling set up and picked up 2. 2 MPG on that alone. Now getting 20 to 22 mpg running around North Ohio and depending on how heavy my foot is. Dynatrac was a little to much $$ - - - SpynTec was almost a swap for both front OEM Bearing packs installed.



I don't have any association with Solid Axel, Inc the SpynTec kit manufacturer except being a very happy customer)

 

[CBlack]

2008 4WD. Just unplugging the EGR I picked up 2 mpg. Went from 16. 4mpg to 18. 6mpg mixed driving.

 

[Cummins Tn]

Ken i am getting the same results out of my truck. Towing the 5er I get anywhere from 12 to 15. (Terrain makes all the difference) But back and forth to work I drive about 25 miles one way and i average 20. 1 per tank. ( hand calculated ) Love the Mods.

 

[KLauber]

Ken i am getting the same results out of my truck. Towing the 5er I get anywhere from 12 to 15. (Terrain makes all the difference) But back and forth to work I drive about 25 miles one way and i average 20. 1 per tank. ( hand calculated ) Love the Mods.

Matt,



Whats your rear end ratio and which transmission do you have? Just got back from a trip to WInston-Salem and back. ABout 40 miles stop and go driving and the rest on the interstate 350 miles (very hilly) and got 18. 4 mpg.



Ken

 

[Newt]

I have a Laramie with remote start. If you unplug the EGR, the truck will start and die using the remote start.

Newt

 

[Cummins Tn]

Ken, Mine has the 373 gear with the 68rfe i presume. I was told it was a Aisin at the dealer
but i think they lied. No worries though. I like the transmission just fine.

 

[KLauber]

Ken, Mine has the 373 gear with the 68rfe i presume. I was told it was a Aisin at the dealer

but i think they lied. No worries though. I like the transmission just fine.

Ask Harvey Barlow about the Aisin, he's got all the knowledge about those trannys. I think you may be right, yours is a 68rfe. The Aisin only came on the Cab & Chassis models.



Ken

 

[KLauber]

It can be stolen then!

I have a Laramie with remote start. If you unplug the EGR, the truck will start and die using the remote start.



Newt

Heard on a radio show that computer hackers can remotely open and start vehicles equipped with such devices. Using a cell phone. Leave a steering wheel lock on that beast!



Ken