Looking for a milage increase. 2006 5.9

[JimB1]

Billvo, Lifted Mega, Put everything back to stock close as possible then get on a dyno and see if hp is low. A 325-610 engine should dyno about 285-545. Possible problem could be extremely retarded timing and the dyno would show low hp-tq even though boost & fuel pressure were withing parameters and truck seems to run ok. Dyno proving/discovery of low hp gives a troubleshooting thread to follow.

 

[AMink]

I got a few flashes done

What flashes? My 06 was built in late 05. I know there is a list of flashes etc. , but I don't know where to look.

 

[BILLVO]

Billvo, Lifted Mega, Put everything back to stock close as possible then get on a dyno and see if hp is low. A 325-610 engine should dyno about 285-545. Possible problem could be extremely retarded timing and the dyno would show low hp-tq even though boost & fuel pressure were withing parameters and truck seems to run ok. Dyno proving/discovery of low hp gives a troubleshooting thread to follow.

His is 100% bone stock and he has not gone to dealer for any flashes yet. I am waiting to see what the smarty junior will have for programming. He is willing to try this for milage only. he doesn't want any more power.

 

[JimB1]

Billvo, My guess is maybe as bone stock his timing is very retarded as a possible factory fault. Dyno should show low hp-tq if that's the case. In any event if mileage is extremely poor and his numbers are, then dyno performance gives solid backup data confirming poor mileage. There has to be a reason and dyno results can help a mechanic troubleshoot.

 

[Lifted Mega]

JimB1 Thanks for your input. I will try to get the truck to a dyno this week hopefully. I will keep you updated with the results. Thanks again

 

[Turbo_Bob]

i currently have 28000 miles in 9 months. My mileage is the same as his. Ive been back to the dealer for the re-flash with no improvement. Went to different dealer no problem found. The truck starts and runs great w/no smoke. I have paid 2 different diesel shops to look at it to see if the could find anything thats causing my horrible mpg. After checking fuel pressure. turbo boost, ect. Everything was well within factory parameters. I did get a smarty from Bob on a trial basis for a trip up to Oregon and running on #1 & #3 and different speeds 65mph and 73mph i actually lost a 1/2 mpg on both settings. I'm still getting 13 mpg at 65mph.

Your engine is OK, the problem, and I dont want to come off here on anybodys bad side, is the lift kit, oversize wheels & tires. I know of two people personaly that have a HD Ram and a Duramax, both are 4x4, auto, with lift kits and oversize wheels & tires. They both removed the tires and installed the stock tires and the MPG improved.



The lift kit and the wider profile tires cause aerodynamic drag. The lift kit and oversize wheels & tires weigh more. It takes more power to get the truck moving and to maintain speed.



Also, the newer the model year the less the MPG will be. Yours is a 2006, the 2003's get better mpg and the older 12 valve Cummins get even better MPG. The 2008's have so much more crap on them than the 2006's for even fewer emisions, they will get even less MPG.



Our HD turcks no matter what the brand weigh 6,000 to 7,000 pounds, that takes alot of fuel to push them around. We should only expect so much from them.



I think a 2006 truck with 4x4, auto with stock engine, wheels & tires, no lift should get around 18 MPG TOPS. .



My truck is stock height, stock wheels & tires, 2 wheel drive, six speed stickshift trans, no fuel mods or timing mods done to the engine, 2003 yr gets 22. 9 MPG solo at 70 MPH and 14. 2 towing enclosed car trailer at 62 MPH. I had the truck weighed and with the shell, full tank of diesel, my 175 lbs. it weighed 7,000 lbs. total.



Hope this helps. By the way oil keeps going up in price, it will soon be $100. 00 per barrel. Diesel keeps going up, in CA the price is now $3. 45 a gallon, 10-31-07. It will be $4. 00 by next year.

 

[Turbo Tim 1]

The flashes done to the wifes truck were



18-003-66



18-041-05



18-032-06



18-005-06



One of them was for a long crank condition and I had heard that one helps mileage so I tried it.

 

[AMink]

Were you charged for the flashes or did they do it under warranty?

 

[NUKEMAN]

Your engine is OK, the problem, and I dont want to come off here on anybodys bad side, is the lift kit, oversize wheels & tires. I know of two people personaly that have a HD Ram and a Duramax, both are 4x4, auto, with lift kits and oversize wheels & tires. They both removed the tires and installed the stock tires and the MPG improved.



The lift kit and the wider profile tires cause aerodynamic drag. The lift kit and oversize wheels & tires weigh more. It takes more power to get the truck moving and to maintain speed.



Also, the newer the model year the less the MPG will be. Yours is a 2006, the 2003's get better mpg and the older 12 valve Cummins get even better MPG. The 2008's have so much more crap on them than the 2006's for even fewer emisions, they will get even less MPG.



Our HD turcks no matter what the brand weigh 6,000 to 7,000 pounds, that takes alot of fuel to push them around. We should only expect so much from them.



I think a 2006 truck with 4x4, auto with stock engine, wheels & tires, no lift should get around 18 MPG TOPS. .



My truck is stock height, stock wheels & tires, 2 wheel drive, six speed stickshift trans, no fuel mods or timing mods done to the engine, 2003 yr gets 22. 9 MPG solo at 70 MPH and 14. 2 towing enclosed car trailer at 62 MPH. I had the truck weighed and with the shell, full tank of diesel, my 175 lbs. it weighed 7,000 lbs. total.



Hope this helps. By the way oil keeps going up in price, it will soon be $100. 00 per barrel. Diesel keeps going up, in CA the price is now $3. 45 a gallon, 10-31-07. It will be $4. 00 by next year.

True story. After I installed my 5" Skyjacker and 37's, my mileage dropped to about 18 overall. I find it acceptable, expected, and not too shabby compared to the wife's '04 Silverado 2500HD with a 6" lift and 35's. She is lucky to see 12 mpg with her 6. 0l Vortec.

 

[Turbo Tim 1]

Were you charged for the flashes or did they do it under warranty?

They did it under warranty, the truck only had 5k on it then and I went in complaining about MPG, I told them I heard the long crank flash took care of mileage plus I had a long crank situation When they hooked up the scan tool it told them the truck needed the other updates.

 

[JohnsonG]

I picked up a little mileage by going to a low restriction air cleaner, a straight pipe, and going to 32's. . all together probably 1. 5 increase... .



I run 150 mile round trip 5 days a week... I shift between 1200 and 1500. barely into the peddle... use the cruise when ever i can. When i was running 70, i got 19 lots of speeding up and slowing down. . the last several weeks I've been running at a max of 55... I fill it till it wont take no more... pen and paper is an honest 24. 3.



I run a bed cover (roll and lock).



On my old Chevy 1 ton, I got better mileage with the tail gate down...



course these newer trucks with there wind tunnel design may get better with it up... .



I've been bugging lady santa for a set of 3. 42s, a smarty and a set of 35's for the back... . :-laf. .



I'll probably have to settle on a new key chain... .

 

[DonFitzwater]

MPG at 7000 miles= 17 hwy. MPG after 2 injectors replaced 7500 miles=18. MPG after flash for white smoke at start up (it didn't white smoke, buddy at dealership recommended it) 21 hwy 15000 miles. MPG after Edge Ez, level three at 19000 miles =23. I am currently averaging 17. 6 in town and not driving like crazy but I'm not babying it either. So far the flash for the white smoke and the Edge Ez seem to be working out. I just saw 3. 25/gallon at the pump today.

 

[Mikie12]

I got my MPG on the rise now, but it cost me big for that. $900. for the TST to advance the injection timing, and $3K for the Gear Venders.
Started out 13 to 15 MPG until 6K miles, 15. 5 from 6K to 8K on the clock, at 9500 miles I installed the equipment and my MPG started climbing from 15. 5 to 17. 3 now with 12K, and still climbing-with more power and lower EGT's to boot.

 

[DonFitzwater]

I never thought that a few miles on these things would help fuel mileage with them being computer controlled but it has really proved true... ..... at least with mine. The Edge really worked out as did the flash for white smoke at start up.

 

[jnelson]

One of the biggest things you can do for mileage in a new truck is givng it time. On my last 4 trucks I did not get really good mileage till after I hit 20,000 miles. Seemed like the longer I drove her the better it got.

Clean filters, clean fuel, clean injectors, and time.

 

[RHestand]

I've just returned to Ca. driving from N. Wi. (2500 mi. ) towing a car on a car trailer, tools, luggage, etc. with combined wt. of 15,000 lbs.

I made almost exactly the same trip last Nov. (same car, trailer, etc. ) with two exceptions :

Free spin front hubs and 30k mi. on the truck as opposed to 20k.

Both times driving 65-70 mph I got 1. 1 av. mpg. better this trip than last. (14. 5 mpg. compared to 15. 6) My best was 16. 2, worst was 14. 6 mpg. All calcs. by pencil.

I have not checked it empty yet, but I think it's also improved a little.

If nothing else I love not having to spin the whole drive-train from the transfer case forward driving down the freeway, plus not having to deal with lubing the stupid front CV.

So far I'm liking it.

Ray

 

[ronman]

... Free spin front hubs...

Ray:



Can you tell the un-educated (like myself) more about these??? What are they, how do they work, what do they cost, where do we get them??? Anything I can do to improve my mileage is something I will consider!! Got a GV OD going in soon, these might be next!

 

[Turbo_Bob]

Just filled up in So Cal, we have the highest Diesel prices around in the US. $3. 66 a gallon, 32. 8 gallons and $120 bucks less. . 20 cent increase in two weeks. Oil is going to get over 100 per barrel, next year the diesel will be 4. 00 per gallon in CA.

 

[Mikie12]

Ron; The free spin front hubs were discussed in a TDR issue, maybe 50 or 51. I'll try to go back and find it for you. I was considering that mod for my truck in the future. It's the old style set up where the hubs stick from the center of the front wheels. I guess you can take your oem hub caps to a machine shop and have the centers turned out so the hubs can stick through.
Still don't have the GV in yet???

 

[VRidgley]

Two recommendations I make.



1. Go to the Carson Dodge web site and pursue adding a cold air box, cool hose, turbo air guide, and straight exhaust. Good for increase of 1. 0 to 1. 5 mpg. $750 installed at Carson, but they could ship you the parts.



2. Install GearVendor Under/Overdrive @ $4,000. RPM will be reduced by 22%, mileage could go from 16 to 21-22. My GV was installed at 25K.



See my charts uploaded at the following threads:



onetank.pdf Miles per Gallon Data

fivetank&cumulative.pdf same

TorqueCurve.pdf Most economical RPM for a 24V?