2004 CAT C13 KCB21422 525hp poor fuel mileage

Message Title: Message Text:  http  https  ftp  mail    hr     highlight   LI   Quote  Select Emotion SmileWinkSadEmbarrasmentDisgustedBig GrinMadShockedTongueCoolFrownConfused [q]I have a 2004 CAT C13 KCB21422 525hp and I am getting 5.4 mpg in my 42,000lb motorhome which to me is poor fuel mileage. I have a friend of mine that has the same engine although I don't know what year and he is getting near 7mpg and his motorhome weighs 6,000 lbs more than mine. I have an Allison 6spd trans and 4.30 gears in the rear. I usually drive around 64-66 mph. I was looking at the FLS and FTS numbers on my computer and they are FLS of 20 and FTS of -34. Can anyone tell me if those are the correct numbers for my engine and if not what do I need to do to change them. I understand these numbers can affect fuel mileage. I also understand that the 2003/2004 year engines have poor fuel mileage but that was fixed in the 2006/2007 ECM program. Can that program be installed in my ECM? I know I am a motorhome but I used to have a Freighliner with an M11 and a 10spd transmission. Steve[/q]

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