MPG update

kw5.9 · Post by **kw5.9** » Wed Dec 03, 2008 10:54 pm

On my last fill up I went 615mi on 28 gallons of fuel hand calculated = 21.9 and never got over 77mph running the performance stack on 60hp

great job diablo!! But i had to swallow my pride more than a couple times and let everybody pass me on the road, not fun, but now that I know I can get good MPG's when i want to, so now I will be smoking like crazy again because it is way more fun to drive like that!
just some food for thought

Post by **mikel** » Thu Dec 04, 2008 11:24 am

Wow, thats impressive....

ranger_dog · Post by **ranger_dog** » Wed Jan 14, 2009 8:12 pm

I have a couple questions, first unless I am reading something wrong, you have a 2007.5 and it has a 5.9L in it? I thought that they changed to a 6.7L in January of 2007 that has a DPF on it and would not allow a straight pipe turbo back? Not trying to stur trouble but instead guenuinely interested in where I can find one of these. Second, and again someone please jump in to either agree or disagree with me so as to save me money in the future, I have a 2006 with a 5.9L and the automatic. I have the predator, K&N filter, modified airbox and intake pipe, 4 inch dual exhaust from the cat back and I run synthetic oil in the truck. I test drove it with stock highway tires and a tonneau cover installed, 3.73 gears, flat ground, windless day, 70mph babied to death and got only 19mpg actual #'s from completely full filler neck start to completely full filler neck end. Asking around, I was told the 6 spd would get a little better but the overdrive and lockup on the auto wouldn't be to far behind. I was also told that I wouldn't see 20+mpg unless I went to a dynatrac freehub kit. So, anyone else getting mileage like this? If your really getting almost 22mpg at 77mph when I can't see 20mpg at 70mph, I need a new truck!

kw5.9 · Post by **kw5.9** » Wed Jan 14, 2009 11:01 pm

yes it is an 2007.5 with a 5.9, you will have a hard time finding this on as i did but they are out there, with puck stack on performnce it got as stated 615 miles on 28 gallons

But i am running full synthic in motor and diffs, stock tires and that day i just put in a fresh fuel filter and cleaned air filter, I wasnt cruising 77mph the whole time i said i hit that a couple times, i had the cruise set at 72 and i really had to baby her also, there was a stretch where i was abusing her a little bit so i really think i can get better, but i was going to settle for an 06' but i really dont like the wood grain int. and I didnt want the laramie pkg, once i saw this 07' and metallic interior inserts i was sold! I really really really like my truck and it has held it own on the street with the stock clutch against some other powered diesels and gassers, I love the predator stack! (but my injectors dont like me very much!)
Kyle

ranger_dog · Post by **ranger_dog** » Thu Jan 15, 2009 6:12 pm

Well I think I am going to look into a 6 speed in the future. I have been planning on a Goerend tranny but I have seen that there are conversions to use a Allison with the Cummins. Since your getting so much better gas mileage, I might also look into the puck. I am running straight Predator. I can't go without the cat though as my wife pitched a big enough fit about the muffler and the duals. Weird though, she didn't notice the silencer in the turbo being removed and that whistle is more significant then the exhaust to me. Anyway, I really am shocked learning about the 5.9 in that late a truck. Not real sure how Dodge got around the emissions laws with that but I guess it really don't matter when we are modifying them anyway. I will have to post an update on the mileage when I get back around to upgrading my truck with the 6spd tranny and dynatrac front end stuff. I am expecting to hit your kind of numbers with my oversized tires. Keep my fingers crossed, though, if I cared about the mileage, I wouldn't be spending the money on the truck and instead buy the new 1500 when it comes out with the new diesel. That truck is supposed to get 25 mpg and who knows what would be possible with the help of diablosport!

GRI · Post by **GRI** » Tue Jan 27, 2009 10:53 am

hey KW. what gears do you have? standard cab of quad cab, long bed or short? what RPMs were you turning while on cruise?

GRI · Post by **GRI** » Tue Jan 27, 2009 10:55 am

and for anyone using a K&N oiled filter I would get rid of it. The turbos on the diesels will suck the oil out of the filter and suck it down the tube.

try a dry filter from amsoil, ice box or AFE has the latest washable dry filter that is the shiz

ozzie · Post by **ozzie** » Tue Jan 27, 2009 8:57 pm

NADP has told everyone I know that K&N doesn't flow enough to keep up with stock deisels never mind after mods. I've got a AFE oiled filter and never hand any oil in the intake hose. Just say'n. It might just be the product.

GRI · Post by **GRI** » Tue Jan 27, 2009 9:02 pm

I got pictures of the AFE and K&N oiled filters with oil trails down the tube.

Just food for thought for peeps looking into filters.

ropnjessi · Post by **ropnjessi** » Tue Jan 27, 2009 10:19 pm

ozzie wrote:NADP has told everyone I know that K&N doesn't flow enough to keep up with stock deisels never mind after mods. I've got a AFE oiled filter and never hand any oil in the intake hose. Just say'n. It might just be the product.

I've had my AFE oiled filter for 3 years now with no oil down the tube..

kw5.9 · Post by **kw5.9** » Wed Jan 28, 2009 8:32 am

hey GRI I have 3.73 in the rear with G-56 manual, its a QC, short box, 4x4 with stock tires, at 70 mph i am turning 2200rpm.
Kyle

GRI · Post by **GRI** » Wed Jan 28, 2009 9:12 am

your numbers dont match.

our trucks do not see the best fuel mileage if you go over 2K rpms. I dont care how anyones truck is set up you will always see better fuel mileage at 2k
sorry but I am going to call BS.

optimal rpm range is 2k or under. sorry
if you said you had a stadard cab,2wd, driving with the wind, down a mountain for half or more of the mileage than its obtainable.
But not with a quad cab, 4wd and running 2200 rpms.

also, if you have under 40k miles on the thing it is still breaking in and hasnt seen its best fuel mileage yet. So it looks like you'll be able to reach 24-25MPG. lol

kw5.9 · Post by **kw5.9** » Wed Jan 28, 2009 10:15 am

you can see the hand calculation belive it or not, and once i get my 33" tire i will be under to 2k and may see better mpgs, but i belive anything under 1850 you will be lugging and there goes ur mpgs, and when i did the test I hag 75,000mi on the truck and now i am at 80,000, my guess -o-meter was reading 27mpgs , i know there are people out there calling BS, i am one of the most sckeptical people there is so if I dont see for my self i useually dont belive it, thats why I did my own test to see what i can get.

GRI · Post by **GRI** » Wed Jan 28, 2009 1:08 pm

I still cant buy it. if you keep your rpms at 1850-2000 you WILL get the best mileage out of the truck. yes anything under 1850 is bad but I dont believe the truck will stay there when doing highway speed. so the likelyness of that happening isnt good.

and yeah you might get the rpms down to 2K with 33s but you wont get better fuel mileage.

Post by **mikel** » Wed Jan 28, 2009 1:10 pm

Whats to say that with the optimized tuning that he cant get better mileage at a higher RPM?

MPG update

MPG update

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RE: MPG update