I am!

I have over 14,000 miles on this truck and have never written down anything above 14.6 M.P.G. in my fuel log book. This truck is driven 95% of the time unloaded and a 70/30 mix of City/Highway driving. I don't let it sit and idle. I do average 75 m.p.h. when I am on the highway though. I thought programming my 285's with the predator and a 40 H.P. tow tune would help but nothing? I am seriously thinking about getting some small car for commuting back and forth to work, it's killing me at $2.349 a gallon. I changed my fuel filter at 7,000 miles and plan to do it again at 17,000. I run full amsoil synthetics throughout the truck. I think the truck should be getting at least 16.5 M.P.G. the way I am driving and maintaining it. Is it time for a LLY Truck? Is there any others with my same concern? Any recomendations?

-J.E.

With stock 245's and a stock ECM I always got 18 mpg +++++

As soon as I added the bigger wheels even with a corrected speedo I dropped to 16.5 mpg....add in the power adder and I am at 15 or so.

Winter diesel sucks and I am getting 13.5-15 unloaded right now.........pretty much stock.

Still way better than my Vortec 7400 was in my 1997.......

You won't save anything with a commuter car..........ad up the cost of the car, insurance, taxes and maintenace and it's way cheaper to buy diesel for your truck.

JMHO

Thttp://www.dieselplace.com/forum/images/smilies/cool.gif NY

16.6 on my lly 70/30 city hwy. diesel #2 about 2.12 galon , but going down in price, so they say.....we will see.............reg at 1.99. this is in san diego, ca. still cant underestand why diesel is more than reg???cost of refine is less with diesel so we all just wonder what the heck is up, is it supply and demand or just a rip off???

still cant understand why diesel is more than reg???cost of refine is less with diesel so we all just wonder what the heck is up, is it supply and demand or just a rip off???
Home heating oil, the right coast uses alot of the stuff when it is cold.

70% is city driving? Stop-n-go driving, what did you expect? Now, if you were 70% highway (even at 75 mph), if you were getting 14, you should be concerned. Winter blend does unfortunately drop mileage noticeably. But would you really want to be driving an 8.1 getting 9?

I'm about 50/50 on miles driven (depends on weekends), and average about 15.5-16 right now in my '02.

Tom http://dieselplace.com/forum/attachment.php?attachmentid=107

your truck is relatively young, not close to broke in yet. i would suggest a quality additive to improve cetane (among other things) and an aftermarket filter system (dont remember if you had this or not. Primrose 405 and the nicktane kit upped my mileage about 1.5 mpg. my mileage also changed around 25K or so. with town driving you are going to lose mileage, dont forget to also account for the difference with the 265s when calculating mileage (if there is any for you)

75mph with the bigger tires is what will kill the milage!!! I know, I drive it all the time. And I floor it to get there too!! :D:D
70% city driving will kill milage too.

During peanut harvest I drive 90% in 4x4 in soft sand. lots of idling and 90 mph chasing parts. Milage during harvest was as bad as 8mpg!! -:t Beats my old 2000 with the 454 that would do about 7 mpg and bog down in the sand.

still cant underestand why diesel is more than reg???cost of refine is less with diesel so we all just wonder what the heck is up, is it supply and demand or just a rip off???You got it, supply & demand - & a rip off.

They (Oil co.) gouge because they can, & right now with all the excuses they can come up with (OPEC collusion, war in Iraq, natural disasters, etc...) they're practically printing their own money.

The fact that most of the present White house administration is "hooked" into the oil industry doesn't help either, they're more than happy to look the other way & they certainly won't make it an issue (I'm not trashing the republicans, I'm just stating the obvious).

So you tell me, who's going to stop the Oil companies from gouging?

I'd say you are doing good if you are driving 75mph. I get 17-18 mpg at 65-70 mph. If I drop it down to 55-60 I can get 20 mpg and if I crank it up to 75-80, 13-14 mpg. If you want better mileage, slow down.

Have to agree with scott ktm on this one. I usually get about 15.5 driving 72-73 on highway 1/2 the time and city the other 1/2. If I do the same speeds he's talking, my mileage is the same as his.

I get 13 no matter what. Towing 8000 pound camper I get 9 MPG.

If I take a trip I get decent mileage, about 16, otherwise I'm running around 12-13. I figure if I took my foot off the floor it might get better, but what fun would that be? On the plus side diesel dropped a little here so I had the 1000 gallon tank filled at $1.75
Should last a while between me and dad. Straight #2 but they mix power service into it. Has worked fine down as cold as it got so far, about -15 one night. Way more with wind chill I imagine.

The city driving and fast highway driving kill's these truck's in economy.
6,500 to 8,000 is a lot of weight to get moving from a stop at light's and stop sign's.
And truck's are about as aerodynamic as a brick.
Mostly city driving I get 12-13mpg on the highway it will jump to 17-18 mpg at a slower speed.
These truck's and engine's were not made to be a commuter car or get their mileage, but they do better than the gas equilevent.

My .02

Diesel Dragon

13-15mpg in the winter, 16.5-19mpg in the summer and thats driving unloaded and at 55-60mph. Pulling a trailer is 12 average. My truck before my DMax was a 95' 2500 with the 454. Diesel has to go to $3.50/gal in order for me to brake even on monthly fuel costs between the 454 and DMax. Forgot to say I also use Stanadyne Proformance Formula year round.

I think I need to try an averge speed of 70 and figure out what I need to do as far as fuel additives and the intervals for adding them. Thanks everyone for your input!

- J.E.

04 lb7 allison. Do about 50/50 highway/city. Drive about 75 on the highway. I get about 16.5 empty. Pulling @ 75mph I get about 14.5ish. 245 tires for now. I have not owned it long 3 months so not sure what to expect in the summer.

I run 265 BFG's. 04-LB7 Going out of Palm Springs on Hwy 10 to Phoenix up the long grade I get 18 mpg and on the way back I get 20.5 mpg and my speed is between 65-70 mph with some passing.

I run stock program, if I use the Predator the mpg drops by 2 mpg.

With my ZF i get about 15 all the time and 18-20 on the open road. best millage is at 55-65 mph on the open road 2 lane or bigger. I lose millage when i run 70 and up. i have 285 75 16 tires. the best millage is with the truck juiced a little with somthing from my collection. usualy only about 80 - 125hp.

so far from what i'm reading here...mods,big tires,bad fuel,flooring it pass 73mph screws with the truck...= leave the truck stock!!!

I have to agree with you Lennox69, but big kids have big toys. Has anyone ever seen an advertisement from GM stating these trucks would get 10, 15 or 20mpg? Fuel mileage wasn't my main reason for buying the D/A, towing & power was. We all know it takes fuel to make power and we're driving the most powerful trucks on the road.

I can pretty consistently get around 20 MPG for straight highway in the Summer if I don't go over 70, don't use cruise.

I was getting 19.2 to 19.5 on trips and 17.2 to 17.4 in mixed city and road driving running 70/75. I went to the 265 10 ply tires and had the service department up date my computer. Miliage went out the window, 17.2 to 17.5 on road trips 70/75 16.2 mixed some times lower.
Pulling drops to 8.9 in mountians and 10.5 in flat land. Still as good gas burner with your foot in it. The larger tries realy knock the mileage.

I got 20.3 mpg today on my way to work.thought that was great...will keep checking.

If you keep it at 1950 rpm's it will get 20mpg.

Mine does.

The larger tries realy knock the mileage.

YEP!!! I went from 20 mpg hwy to 17 mpg, and 18 mpg mixed to 15.5 mpg when I switched to 265's. This is after I re-calc the mileage to allow for the larger diameter/ less revolutions of the 265.

Hey LB7 I use this additive called Mile Max. Used it for the firstime on a trip to Elko and it really bumped up the mileage. It boost the Cetain (sp) Number by 3 and helps with water and other stuff. my .02

FP could help MPG, give it a shot.

Example: http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=002845

I don't know about you guys buy I will take 14 M.P.G. before I drive a GMC 2500HD with four rough riding factory spare tires on it!- J.E.

they need a higher overdrive or a 2 speed rear end in the worst way because well all know that we can give them the ponys to get them in that higher gear and keep it there!!!!!!!!!!!!!

GM is as much the problem as the solution!!!!!!!! They could still have the 410 rear end and just change the high end gearing......they are so pathetic that they prolly use motor oil to fix there hair in the morning to keep the oil companies happy!!!!

i pull an 8000 lbs fifth wheel, with a 900 lb golf cart riding on a snowmobile trailer and i can get 12-14mpg. that's also loaded down with "stuff" for a week long vacation for me, my wife (there is a 1000 lbs of "stuff"), three children and a 90lb rottweiler. i also have 3.73 gears in my 02. did yours come with 4.10's

I Have 315's And 6inch Lift And W/primrose Additive And Pred On 65hp I Am Getting 14.8 -16 With 75-80 Hwy 70/30 Hwy/city Driving . For Me I Think It Depends How Much You Get Into It From A Stop Light But On The Hwy At 75 My Rpms Are At 1950-2000rpm

I say get rid of the Scamsoil and your mileage will improve ! -:t

Both my '02 and '04 increased fuel economy noticeably in the 14-16k mark. Like others have said, run some DFA with a decent cetane boost. In the summer I am getting 19 running 70-74 mph 70 % highway 30 city. Over 70 it goes doooooown quick. Now with the winter blends I run 70 % city, 30 highway and I'm at 14.5, nicktane, stock tires, DFA. All my gassers used to get 14 in the summer going down hill with the wind at my back on a good day. Like everyone else I'm pretty damn sick of paying more than premium for fuel but I still believe this will cycle back to where diesel in less than regular.