As to the mpg, I have never seen 20mpg in my life. 25 or better sounds cool, would not be a factor in buying a rig though
I had a 2015 RAM Limited Ecodiesel. I'd done quite a bit of research on the mpg and after I bought it learned about all the ED issues. I talked to an awesome RAM investor and high performance diesel mechanic and he told me what to do with it for longevity.
1- remove all the silencing "death foam" from on top of the motor, valve covers, and fuel pump. all this stuff does is hold in heat on critical wiring and electronics.
2- pull the EGR intake tube and see how bad the intake was coked up. it was awful. he told me the right things to say to the service manager at a local dealership, and to make a long story short, they replaced the intake and my injectors under warranty.
3- sign up for the class action lawsuit and take the money and invest in a tune. i was able to get the Green Diesel Engineering non-epa compliant tune before they put the clamps down. it effectively turned off the EGR electronically. i got mine with transmission tune also, and it improved the shift points and included engine braking as well.
The engine tune added around 30-40 net horsepower and 40-60 ft. lbs of torque. However, the greatest benefit was elimination of the EGR and all the soot those little motors pour into the intake. With this combination, I averaged 27 mpg combined and over 30 mpg crusing the highway. I got 23 when pulling my 17' Lund deep V and the engine braking and overall towing experience was awesome. The tune woke that motor up big time and it would even spin the tires off the line if I needed to gun it.
When I hit 110k miles, I learned about a tone ring issue in the transmission that was sidelining guys around 115-120k miles without warning. The part tat failed was about $20, but when it failed it would break apart and cause catastrophic damage in the tranny. This issue affected a significant percentage of these trucks and repairs were upwards of $4-5k. Add the risk of turbo line fires in the engine compartment and I decided to trade it for a '19 hemi.
Given the increase in my monthly payment and overall driving experience with the hemi, in retrospect, I wish I would've fixed the tone ring and turbo line issues. in the '15 That truck was the total package with good power, excellent mpg, 4 corner air bag suspension, crew cab room, and plenty of off road capability. Hindsight is always 20/20.
