I have the 3.55 rear end. I figured that with 8 gears the engine could happily downshift if it wanted a higher rpm. If a person spent time on hills so severe that 1st gear wasn't low enough, then I guess that would be the time for 3.92.
The warts. If you poke around the relevant forums you'll find folks complaining about CELs. I've no idea how many people have this trouble, because most truck owners aren't in the forums and people w/o a problem don't post about it. That said, I have an intermittent CEL. I don't recall the code off the top of my head, but it was something I judged as non-critical.
A lot of folks are getting the problem fixed with a software update. Those that are hosed have trucks at dealers that decided that some piece of hardware was also needed, and since this is the first model year for the truck, RAM is struggling with spare parts inventory. My estimate of the situation is that if that latter group had just done the software update, most of them would have been fixed.
Heck, in car repair the % of perfectly serviceable parts that are replaced as part of a repair is pretty darn high.
Engine management is complicated as hell. The average consumer expects to take a problem to a dealer and have them execute a 100% sure solution the first time. But the real world doesn't work like that. Every complicated system has quirks. It takes time to figure out what is the genuine source of a problem, vs. time and energy wasted trying to fix symptoms.
I've carefully monitored the behavior of the CEL over the past couple of months. The truck's power and mpg efficiency are unimpaired. The CEL seems to be related to going easy on the truck, which by nature is how I drive a DD. It doesn't occur when towing.
I'm a couple thousand miles out from the 10k oil change. I figure I'll bring the intermittent CEL to the dealer's attention then. The longer I wait the more spare parts inventory I'll have, and the more experience RAM will have with the problem.
