Engine/Transmission (1998.5 - 2002) GOTTA freakin LOVE IT!

[WadePatton]

I just calculated the mileage on my last tank of fuel. 512. 9 miles, including five pulls on the dyno and me still playing with the new-to-me power of the injectors and many many hard pulls to test the new Wildcat Maximum Flow line upgrade.



26. 86 gallons of #2 including 16 oz. of Power Service comes out to 19. 09 MPG!







As I casually mentioned my new dyno numbers to my cousin today, he said, "yeah, I bet that thing gets 6 MPG. " WRONGO!



So keep telling the SO or (CO for you married guys ) that them BOMBS SAVE MONEY--eventually.



I'm going to poke around for a half-tank on 2x2 and see what numbers I can turn.

 

[GeneralMachine]

polk Around

It's sure gona be hard to pull this test off. Harv:-laf :-laf :-laf

 

[snowracer69]

Jeezus!!! :--) Those numbers are awesome. Maybe it's cause I'm at such high altitude or that I drive everywhere hard, but I'm only getting about 16. 5 w/ my 3's and the Drag Comp.



Maybe if I go to lower altitude where she won't smoke quite as much...



Josh

 

[Rebel_Horseman]

I almost fell down today when I filled up. Figured it out to be 18. 88 mpg! That's noyhing but a K&N & straight pipe. I can't wait to see what injectors and a box will do. Sad thing is, I never ever saw those figures out of my Duramax with AmSoil filter, straight pipe, and regular Juice.



Reb [><]

 

[John]

Great numbers Wade!



Josh, I also have DD3s and a drag Comp (among other things) and get about what you do... in the middle of the winter. I get about . 5-1. 0 mpg better than your stated number in the summer.



On another note, a gal I occasionally work with told me and another co-worker that her Duramax powered GMC 4x4 (Allison)... towing her four-place horse trailer no less... although I don't remember if she only had 1 or 4 horses in the trailer at the time... got 23 mpg! Keep in mind we live in Western Washington and she had to travel over several mountain passes to her destination in Eastern Washington. My buddy thought I was gonna lose it and launch a nuclear-style BS attack her way (he's a Ram V-10 owner) however, I calmly paused, and asked her if she was going by the data provided in the overhead console. She stated she figured it out for herself!



In-friggin-deed!

 

[JaMan]

I used to get 19. 5 but now it sucks (fuel) and I get a best of 16. 5 with no changes in hardware. :{ Why me ??? and no DD3's. Maybe I'll find some silly reason why someday, till then Congrats Wade





Jared

 

[JCyrbok]

Mileage

Just ran 20. 22 miles per gallon over the holiday weekend. That was stock filter with Fleetguard elemen/no bombs. I do run Amsoil. I just put on a TTPM this past week so We'll see what that does for her and I'm waiting on a replacement element for my Scotty II that was damaged.



The 20. 22 was pretty much all highway. I average 17 in "mixed" driving. U gotta love a truck this big getting that mileage!



J-

 

[Cummins4Life]

Ran 600+ miles between here and Portland on 2x3, ranging between 55-75mph and up over Willamette pass both ways and got 21mpg, suprised the heck outta me when I'm used to getting no better than 19 with the box off.

 

[powerwagon440]

all i have to say is " how the heck r u guys getting this mileage???" dont get me wrong that is awesome U GUYS r getting this mileage! im not even getting 15 mpg on my 99 and all i do everyday is drive 30miles and 30miles back! and i cant wait to c what it will do with DD3's and a drag box probally under 10 LOL hope not anyways great numbers!! Andy

 

[Hohn]

Originally posted by JaMan

I used to get 19. 5 but now it sucks (fuel) and I get a best of 16. 5 with no changes in hardware. :{ Why me ??? and no DD3's. Maybe I'll find some silly reason why someday, till then Congrats Wade





Jared

Try cleaning your IAT sensor. That seems to be the most common cause of poor mileage out of thin air.



Hohn

 

[WadePatton]

Originally posted by John



On another note, a gal I occasionally work with told me and another co-worker that her Duramax powered GMC 4x4 (Allison)... towing her four-place horse trailer no less... although I don't remember if she only had 1 or 4 horses in the trailer at the time... got 23 mpg! Keep in mind we live in Western Washington and she had to travel over several mountain passes to her destination in Eastern Washington. My buddy thought I was gonna lose it and launch a nuclear-style BS attack her way (he's a Ram V-10 owner) however, I calmly paused, and asked her if she was going by the data provided in the overhead console. She stated she figured it out for herself!

In-friggin-deed!

I had almost the same situation with the GF's dad. He knew I had him beat HP wise, so he started the PSD-pulling enclosed racecar trailer 26 MPG story. I smelled the BS IMMEDIATELY. 16mpg empty I would have bought. Anyway-- I let it slide. Heck I've been to the dyno since then, maybe he's up to 30mpg now. :-laf



As to LOW mpg-- these engines vary a bit. Some folks have a hard time breaking 16, while lots of us do 18-19 without trying, and then there are those that get 21 or better. Some of it is driving style. If I "blow smoke" all day long I'll go into the low 18's maybe 17's. If I kittyfoot it on pure highway--22. 5 last attempt, but that's a pitiful way to drive unloaded.



Lots of threads on mileage fixes. Summary: first make sure you're odometer it dead accurate--or your correction factors are indeed correct. Second, clean/replace the IAT or check its function with a scan tool. Then make sure you don't have boost leaks. Verify LP function. Kill the Cat (12v only). Don't lug it. And if you're under 50k-- the mileage will probably get a little better on its own as things loosen up.



And keep the wind at your back and go downhill mostly!

 

[powerwagon440]

brand new IAT sensor! didnt change a thing. owell i guess

 

[kiwi bird]

I love my truck! I get mid 18s most all the time but had to drive from Los Angeles to Modesto a couple of weeks ago and sat at 90 mph for most of the trip and got 19. 3 mpg.

 

[lizzyhermit]

Kanab, Utah to Phoenix, AZ

Labor Day (can you say HOT!)

('cept Flagstaff was 57 f and raining)

around the speed limit

22. 9 mpg

I'm happy

 

[hdtrukn]

Mileage Factor

How about a little comparison.

Guys with bigger than stock or Mud tires, MPG

Guys with stock, street tread tires, MPG

JaMan any chance your mileage dropped when you put on those

305/70 meats.

Big tires look neat, but at a cost of MPG.

A 2. 5mpg loss is about $7. 25 PER TANK.

Just a thought.

Scott

 

[JPLB22]

As you can see in my sig my '02 is pretty much stock. 4" from turbo back is only significant mod. I still have the factory 265 Mich's ( which I like quite a bit ). Around town I like to goose it pretty good when getting on the freeway and leaving stop lights ( but I DON'T beat the pi$$ out of it though ) and I average mid to lower 18's. I recently returned from an 800 mile round trip. 100% freeway at 80 - 85 mph unloaded, mileage was 19. 75 mpg ( figured using a calculator ). I was sure that I would break 20 mpg for the first time, but I was still quite pleased anyway. My truck has 25,700 miles on it.



My good friend has an '03 powerstroke 7. 3 and on long freeway trips unloaded at 80 - 85 mph he is consistently getting 20. 2 mpg. This suprized me quite a bit, but he is someone I definately trust. His truck has 4" fromt turbo back also and no other mods. He has factory tires also. He figures his with a calculator too.



We both talk about taking some long trips at 65 mph but neither of us think we could handle that for very long.



Jeff

 

[JaMan]

I think I fixed my problem a major boost leak that I created when I installed my injecters, so now maybe I'll be back in the upper escelon of mpg's like Wade (but not with near the Hp. ) Still good for now, and maybe tomorrow, Man I'm a milage and power junkie, I never should have bought a diesel. Not enough time and money, yet nearly endless possibilitys! Oo.





Jared

 

[WadePatton]

The trick I used was to only run PART of a tank at 70mph. Then refill and drive as normal. I'd go crazy doing 70 on a divided highway with no good reason except fuel consumption.



I should have a good tank coming up. Last tank was right at 19--with a few top-end runs on it. Figured with a pencil in a hurry. The next fill-up will have 3-4 hours of slow highway driving with a canoe hanging out the back.

 

[JaMan]

Just finished a milage test and (drumroll please!) 18. 8 mpg the boost leak was a major power and milage thief. The milage is back where it should be. And my truck is 4x4 long bed with lots of iron and 305 muds. I AM HAPPY again Oo.





Thanks Jared

 

[jmtandem]

mileage

Tacoma Washington to Carson City Nevada, about 800 miles at 70 mph, 21. 5 mpg. Truck is stock except 285 tires that create a 9 percent odometer error. The 21. 5 mpg is the corrected number.