I use SCT to tune my show/drag truck, a 99 Dodge Dakota R/T. It works great for a high performance application. Now, that said, I just can't justify the expense of the 5 star tuner for a motorhome! Spending over $500 bucks for no gain in mpg seems a HUGE waste! I can deal with the peculiarities of trans shifts and climbing hills a little slower. Driving/site seeing in the motorhome is supposed to be a slower more relaxed experience anyway. As always, we all have our own point of view and reasoning.