C4 Max

Has anyone in the Phoenix area had a driveability or a mileage flash done? I asked about it and they said they had done it to a shop truck and it made it a lot worse. So I told them not to till I can find out more about it. If you have and had good results, can you post the tsb #. I don't have any of the white smoke, hard start symptoms, but the mileage still sucks. I know I need to wait till she's broke in, but I'm at 7000 miles and still at 14-15 max hand calc'd. Should I wait till 10k or so? Thanks in advance.

Hounddog

Alll the post I have read said it improved mileage,trans shift etc,.

goose2

I can tell you from first hand experience. I got the flash done on my 06 at 4500 miles on the odo. It pretty much made a new truck out of it. It now has more power on the bottom, mpg went up atleast 2.and the shifting is a lot smoother than before. Needless to say, I was happy with my truck before all this. Now I am "extreamly" happy with it.

J BODY

For what it's worth I did the flash a couple weeks ago on a customers rig and he stopped by yesterday and gave it the thumbs up for mpg.

wksaz

Phoenix area MC owner here and I have been to my dealer twice and they say I have the most up to date flash for the truck. My mileage is still really bad. I drive a 50-50 mix of freeway and street driving and I am getting about 10.5 and have 5000 miles on the truck. I do not "drive it like I stole it", I try to keep revs below 2000 or around there and I know how to drive it. I have over 1,000,000 highway miles under my belt, and have never had these kind of differences before. My problem with all this is that I am being told that it will break in and loosen up after 15-20K miles. I have a hard time believing that I will ever hit even 15 mpg starting with such bad mileage. I hear reports of 14-16 with fresh off the lot trucks, and then improvement to the high teens or 20, what gives?

Maybe J BODY can shed some light on this. Could you possibly PM me if you do not want to post a response. Maybe I have a bad service writer or dealer. Thanks in advance.

P.S.
As of Wed. I just installed a Rokktech crank sensor to advance the timing a little and so far my overhead has begun to move up. It says a whole 11.2 now, but it has only gone 100 miles or so. I will post follow up if I see some progress.

I really LOVE my truck, just a little disappointed that they tole me I would see better mileage than the PSD I traded in. (17.0) Driving the same loop, 44K though.

tacook

C4 max...........15 mixed driving isn't to far off from normal.
It will go up slightly, but not much. I have 4 2005 and up dodges at work and we all get the exact same mileage.

Mule Man

14-15 in town is what I get. Some of that includes a daily run of about 15miles on the 101.The rest is stop and go. On the open road with nothing trailing or much in the bed at 80 I get the same. 11000 miles. 3.73, 35's 3500 Mega, 4x4

TonyB

I had the flash done while I was in Oregon, back in June. I have seen the freeway mileage improve from 15.3-16.5. BTW...this is hand calculated. I also only have 6500 miles on the truck.

This week, I have seen the overhead jump about 0.5-0.75MPG higher. My over head consistently reads 2-2.5mpg higher than hand calc. It'll be about another week before I need to refuel...I'll check mpg then.

HTH

Tony

C4 Max

Thanks guys, I go in Tuesday for the recalls and will check on the updates again.

J BODY

I've test drove 3 trucks this year for repeat "poor mpg" issues. Filled tank until I could see fuel in the neck. Drove it on a 60 mile round trip with GPS along. Filled at the same station until fuel showing again (this does take awile). All three I was able to acheive over a 17mpg average. Keep in mind they had a percieved MPG PROBLEM, so I drove it to get maximum results. What would I do if the results only came out to 14-15??? not sure to tell you the truth.