Engine/Transmission (1998.5 - 2002) Fuel Mileage Dropped

[LBTRS]

Hello,



I just returned from a 1500 mile trip and my fuel mileage was down a lot from previous trips. On past trips I could get 21-22 mpg with all highway driving. This trip I was getting 17-18 mpg (all hand calculated).



I recently had the ECM fail and the dealer replaced the ECM after sending it to Cummins Northwest in Spokane Washington to be flashed since they could not do it in their service department. Is there anything in the ECM flash that could have dropped my mileage this much? The mileage on this trip was more like I used to get with city driving.



Thanks for any help,

 

[John - K5AWO]

Lost mpg from ECM reprogram

bah humbug on the EPA. Your lost miles/gallon are because of the ECM reflash you received either thru the new ECM or your old one after it was reflashed.



A friend of mine was getting 26 mpg on his truck before the flash on cruise hiway driving at ~60-65 empty tailgate down. When he allowed the reflash recall to be performed he lost 8 mpg and the best he can get with very careful driving is 18.



If you want your mpg back, you are going to have to add performance enhancing methods to get it done. Before you run off and do that, calculate how long you want to keep your truck, how much the upgrades will cost you, and then take that cost figure and divide that by the "mpg gained". Break even is going to be a long way in front of you. PITA in my opinion.



I just cannot fathom how the EPA figures that taking a vehicle that can go 26 mpg on a gallon of fuel is going to emit LESS polutents if that same vehicle can now only travel 15-18 miles/gallon. There is no way you get cleaner air under those numbers.



Sorry you had the bad experience. Me, I am going to get an Edge EZ and the stainless steel exhaust system special from Piers Diesel. $750 for the package deal according to Harry when I talked to him this morning.



Harry said not to expect more than 0. 5-1. 5 mpg improvement even at that, but the power will return to where it was before.



Enjoy what's left of your day... .



John