Update flashes and mileage - Diesel Truck Forum - TheDieselGarage.com
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post #1 of 7 (permalink) Old 11-06-2009, 12:04 PM Thread Starter
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Update flashes and mileage

Twice I've had to take the truck to the dealer to deal with a CEL. Both times they did flash updates and the second time a new turbo too. My mileage seems to have dropped significantly with the flashes. I only have 18k on my '08 truck but before the flashes I could get 19 mpg highway. Now more like 16mpg on same trips if I'm lucky. Any thoughts? Did they reprogram the truck to run differently to avoid more CEL's but costing me mileage?
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post #2 of 7 (permalink) Old 11-06-2009, 12:27 PM
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I have had my truck in the dealership many times as to the point of lemon lawing it. Everytime they say it needed reflashed. I think if I remember right it has been reflashed 9 times and I just went on a 200 mile trip. I got 18.7 by the overhead and that was running around 70 to 75 miles per hour. I have seen 20 miles per gallon before on the interstate so I don't know if maybe I got some bad fuel or it was my driving but I seem to stay around 19 on the highway. Hope this helps.

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post #3 of 7 (permalink) Old 11-06-2009, 01:31 PM Thread Starter
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Thanks. Sounds like its other factors and not the flashes.
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post #4 of 7 (permalink) Old 11-06-2009, 05:08 PM
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The best I have ever got is 17 mpg, only mods are a CAI and 33" tires. Reflashed twice now, and mileage hasn't really changed.

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post #5 of 7 (permalink) Old 11-06-2009, 07:59 PM
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The best thing for these trucks is the latest flashes and a Smarty. I have the AZ flash on mine and will not get another flash. My truck is running tooo good.
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post #6 of 7 (permalink) Old 11-08-2009, 06:09 PM
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Ok i hear you all talking bout your mpg now how many miles can you go on a tank of fuel??? Like i have a 34gal tank but i run the wit the light on for awhile and usually put 31-32 gal in.

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post #7 of 7 (permalink) Old 11-08-2009, 10:32 PM
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Hey Guy's,
On the highway all day I can go about 550-600 mi on 32 gal.
In the city just under 400.
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