Now that the reflash has been out for a couple weeks, I see alot of post of improved computer readout mileage. How about we get some figures of old verse new calculated by hand. Thanks still sitting on the fence on this one.

Old Fuel Mileage Comp/Hand New Fuel Mileage Comp/Hand

 

With over one week of travel, approx. 75 miles per day to from work with a 50% highway (at 70 mph+) and 50% freeway 55 to 60 mph, have notice about a 2.5 mpg difference in MPG when calculated by hand, computer is closer to what I am calculating at 19.7 mpg's up from 17.2 mpg (hand calculated) on my 2004.5 600 Quad-Cab short bed stock with 9600 miles on it.

I have pulled over 8000 lbs on it several times, babied it when I first got it, warm up and cool down appox. 3 mintues each and also have a vinyl cover over the bed to reduce tailgate drag.

I am hoping it will soon hit 20 mpg.........................................

 

Hmm must be nice. Well before the reflash, mine was getting 12.5 avg on the Computer, and 12.3 by hand...
After the reflash I get 17.3 Computer and 13.8 by hand

It must be due to the huge tires and TST...

 

Have you had your speedometer re-calibrated?? That will make a difference cause your truck thinks its not going as far as it is.

 

Nah, I haven't messed with it. I figured it to be right around a 1.6mpg add on by hand. So 13.8=15.4 which isn't so bad I guess. But it's still horrible compared to my 02...

 

I took my truck in and they said are you having an smoking issues... I said no..... they siad well it is best only to treat issues... and have you start having problems bring it back... then I said what about the mileage issues.. The guy stated you only have 600 miles on it... etc, etc.. In the end he said to check it by the 100 or so mile hand cal... and bring it in if it does not match the computer.....

Should I just take it back in and say flash it??

ps: so if I am getting about 15.0 avg in city highway 60 - 70 mph... and street avg. ofcourse less..... WITH only 600 miles on the truck... What kind of avg. should I see once I hit 5000 miles ??? Are those good really good numbers for 600 miles...

ps2: should I start putting additives in all ready?? Whch is going to bring up another can of worms... I drove to the south side of town... went into 2 truck stop "service" area where they are working on engines the size of 2500 truck bed.. but they did have the cummins sign outside... I asked the time bomb question about putting fuel additives in and both siad no, no, no... so I drive home just wondering... because this is all new to me...

 

Remember ghostbusters? "If someone asks you if you're a god you say...YES!" I'd wait, take it back, and say "the overhead is wrong, and it smoked a bit here or there".

At least here I could say "it smoked really bad the two cold days we've had, today wasn't that cold".

You don't need additives. I put one in when I question the fuel quality, or if I'm worried about cold weather.

 

I just had reflash done today. Puled 5th wheel to Durango, CO for a little fall vacation and decided to have the reflash done at the local dealer. They were happy to accomodate. I have about 1,725 miles on the truck and averaged about 12 mpg towing from Calif to Colorado.

Since the reflash the truck seems to have more power and is getting about 2mpg better from the overhead. I am leaving Friday to return to Calif with my fiver. Hope to get 2 mpg better which will end up saving me about $100 in fuel for the journey.