The 42rle does do that (as do other transmissions), but why did the Chrysler engineers design the tranny to do that? Is it really because higher rpm's are not good for the engine? Is an engine-tranny combination right just because it runs lower rpm's? Why is the 42rle almost unanimously hated for it's 0.69 overdrive?
My understanding (and perhaps someone more knowledgable like
@mrblaine can comment on this as to whether I'm wrong or not) was that Chrysler used the 42RLE for the TJ because it was a transmission they were already using in many of their other FWD vehicles. It was never a clean sheet design or anything, specifically meant for the TJ.
In addition, I've read things here and there in the past that mentioned the ridiculous overdrive ratio and constant low RPMs it keeps you at were a result of Chrysler trying to meet emission standards.
Again, I don't know if that's accurate, it's just what I've read.
I really don't care who says what, a 4.0s optimal cruising RPM on the highway is certainly not under 2000 RPM. I mean sure... if you want to live with that and think that's acceptable, then by all means, be my guest. I think the majority will agree that it's mind numbing.
So yes, while everyone is entitled to their "opinion" on the matter, I think that the majority of people are going to agree that keeping the engine at higher RPMs (above 2000) is going to be better.
In addition, I've heard from
@Jerry Bransford and others that consistently keeping the engine at low RPMs thinking that you're "saving the engine" is actually bad for the engine. I'm not the expert on this matter, but it makes sense from things I've read over the years.