ronandsue74 Report post Posted June 4, 2014 I recently called the Cat hotline to ask them if my ECU flash needs to be updated. They could not tell me when it was flashed last. Todd's recommendation was to NOT flash the ECU unless I'm having issues, which I am not. I told Todd I was hoping to improve my MPG by having my ECU flashed. Todd said that an MPG improvement is possible but not everyone see improvement when they have their ECU flashed. I'm looking for feedback from anyone who has had their ECU flashed on a Cat C-9 engine. Did you see any fuel economy improvement? Thank you in advance for your input!RJ2005 Inspire #51264. Share this post Link to post Share on other sites
wolfe10 Report post Posted June 4, 2014 RJ, Todd gave you sage advice. There is a high likelihood that the most current software will NOT address MPG or performance, but will address emissions. There are those three variables. The software is a juggling act between MPG, HP and emissions. There are other things to do if you want to improve MPG: How many miles on it-- initial valve adjustment around 30k miles. What speed do you drive? Drive in regular or economy mode on the Allison? Brett Share this post Link to post Share on other sites
ronandsue74 Report post Posted June 4, 2014 Brett, I have 37k miles on it. I had the valve adjustment done in Dec of 2013 by Holt Cat in Dallas. I drive between 62-65 mph. I always use the economy mode, unless I forget to engage it. My loaded travel weight is 30,680 + 4,840 lb toad = 35,520 gross weight. I average 6.6 mpg. 2005 CC Inspire 330 #51264 RJ Share this post Link to post Share on other sites
