21.9 Mpg @ 80mph

[bill8333]

Ok this is one for the books. A brand new 2004 2500 QC S/B 4x4 with less than 1000 miles on the clock getting 21. 9 mpg ?? @ 80 MPH how can that be. In fact if I slowed down the mileage went down. Has anyone had this happen.



Bill7975

 

[E7mack96]

give me a hit of whatever you are smoking.

Ok this is one for the books. A brand new 2004 2500 QC S/B 4x4 with less than 1000 miles on the clock getting 21. 9 mpg ?? @ 80 MPH how can that be. In fact if I slowed down the mileage went down. Has anyone had this happen.



Bill7975

 

[GCross]

Some how you miscalculated, your best mileage will be at 55-60, past that you will pay a wind resistance penalty, how much will depend on many other factors.

 

[Larv]

Ok this is one for the books. A brand new 2004 2500 QC S/B 4x4 with less than 1000 miles on the clock getting 21. 9 mpg ?? @ 80 MPH how can that be. In fact if I slowed down the mileage went down. Has anyone had this happen.



Bill7975

You did something wrong! Way wrong!

Larv

 

[tschwab]

Probably has the OHC set to km's instead of mpg's.

 

[jersey diesel]

Mpg

Hold on there guys, His overhead comp. could be defective. Or he may have been going down hill. Steve

 

[hammersley]

Don't believe the overhead console --

:{ Just take your foot off and coast -

 

[PJ]

What brand truck and trailer was towing your rig when this happened? Was it behind an AAA tow rig? :-laf :-laf

 

[XJSuperman]

It's feasible he got 21. 9 MPG on the truck. With my 305/555 when it had less than 1,000 miles on it we went on a 700 mile trip and I got hand calculated 21. 8 MPG round trip all highway running 75-80 MPH. I've reproduced this mileage since then again hand calculated so I know it's not a fluke... mind you it;s been all empty and no trailer. I'm getting 17+ avg city and 20+ avg hwy.



With that said... I would be interested to see what his actual mileage hand calc is... I don;t trust the overhead at all. It's told me I was getting 41 MPG at one point while cruising down the interstate.

 

[Larv]

On my 04. 5 the overhead is off as was the overhead on my '99. I've filling up until the pump clicks off and then putting in another 4 gals even tho I think I could probably squeeze in another gal. The overhead is always short vs hand calculated. If the overhead says 16+ the hand calculated is 17+. I've been getting 17 - 18 mixed mileage. I would expect 15 - 16 if all city driving and maybe 18+ if all fwy. On the fwy I do keep it at 2000 rev's, about 65 - 70 mph. So far very happy with the truck!

Just my . 02 worth.



Larv

 

[PJ]

For some reason, my 305/555 got over 20mpg also and that was on the first tank @ 65-70 . After a few thousand miles, the mileage went down as the motor broke in. When I traded it off a few months ago, I had 13k on it and the avg was about 18mpg on the highway at 65-70 mph. My new 325/600 gets crap for mileage. The only thing I gained whith the TSB was smoke at start up in the mornings, but by the time I get to the end of my driveway (about 1/4 mile) its is gone or i just dont see it in the rear view mirror. The best Ive got in the new truck is just under 18mpg and that was with the cruise on at 65mph and the truck was totally empty. Pulling my 30' trailer to the coast a few weeks back, I got about 12-13 @ 55mph. Not bad but not that great. I still love the truck! Oo.

 

[Briman]

I read this post earlier and knew Bill was going to get flamed from all you empirical wizards. One of my best milage occurences was on a trip accross Wyoming and I got 21. 42 (450 miles). I was traveling at 78 mph with cruise control set. I also had a 40 mph tail wind. I know that does not satisfy some of you because of fill up discrepancies. On the other hand, the worst I've gotten is 8 somthing, once again, the fill up discrepancies raise their ugly head. I have gotton 18. 74 average since buying the truck. Over a thousand gallons of fuel ingested. One of the big differences here is that Bill has an '04, he will almost always get better milage than a '04. 5 or '05. I am amazed at the power and economy my '04 provides. It is evan better with intake, exhast, and advanced fueling curve. All my milage is hand calculated.



My hit. :--)

 

[bill8333]

Sorry guys. Yes I did both hand and the over head computer. I was 2 tenth off because I didn't use the . 74 on the gallons. One way 476. 2 miles gallons used is 21. 74 believe it or not guys.



Y'all have a great thanksgiving

 

[red-rider]

Oo.

Im a new member to TDR and very happy to have joined. Just traded my 1500 Dodge 360 for the 2004. 5 2500 HO Diesel and no regrets. Alot of BS from regular fuel 2500 Heavy Duty chevy owners, but when we travel to Glamis, CA I only use alittle bit above half tank towing my toybox and they use 3/4 tank also towing their toybox, they start wondering if they too should invest in a diesel.



I have hit 24mpg @ 60mph freeway, worst was 18mpg @ 70mph, I also hit 11-14mpg city driving. I love this truck

 

[PJ]

Bill7975... Is your truck a 305-555 or 325-600? Have you done any mods at all? I guess anything is possible. i remember last year when I rand my first tank in my new 04 305-555. It was between Grants Pass Oregon and Chico Calif. I had my foot in it all the way and got over 20 mpg. I posted it and got flamed bad. My mileage was about the same for about the first 5k miles and then went slowly down after that until the trade in time. I figure it needed a new fuel and air filter. Maybe I should just trade my trucks off just before the 15k service is due! That was in fact one of the excuses I gave my wife when I made my new deal. I told her that I woulod have to lay out about $1,000 in service and for another $2,000 I could upgrade to zero miles, a year newer, and a 1 ton. :-laf She went for it! :-laf My only regret is the mileage and the start up smoke. Im just waiting for the next TSB on the smoke. Everyone at the dealer and at the local Cummins dealer in Medford say I have nothing to worry about. The Cummins guy says my mileage will come up in about 15 to 20k. . I guess we'll see, unless I get the new truck urge again next year! . Geeeezzz, What am I saying? I dont even have my plates from DMV yet :--) :-laf

 

[roperteacher]

My overhead computer is way wrong the other way. . It says I am getting about 2-4 MPG BETTER than I really am!!!

 

[KennethS]

I got a new dodge dually and only getting 15 and that actual. Someone talking with forked toungue I would say. You would half to show me to make me beleave that.

 

[coobie]

I get about 17-18 mpg,s driving at 65 mph. When I drive at 55-60mph my mileage is between 19-20 mpg,s. My truck just turned 15,000 miles. I use stanadyne performance formula every tank. I have the 305/555 motor. coobie

 

[BHolm]

You guys crack me up!

This site is such a pleasent change from the Chev diesel site I spent time on when I had my Chev Duramax. Those guys fall all over themselves bragging up the milage on those trucks. Someone here posts a big number and the "fact finders" want to know how and why, and NO WAY is the consensus. At the Chev board, they would puff their chests and again proclaim to have the best diesel engine. Finally a site where guys actually care about the truth, brand loyalty be damned!



Anyway, my '03 quad gave me 19. 6 mpg travelling at 85-90 on a 300 mile trip. The truck was still pretty new. My new '05 just gave me 18. 3 on the first tank of mixed driving (empty) I am taking it on a 3000 mile road trip next week. I will report what I get, and I'll be honest about it

 

[hammersley]

Ok -

Holm - is yours a 2 or 4 WD - and axle ratio?????