Underpowered? As compared to what? I had an 95 Explorer Sport with a 4.0 V6 that I traded for the H3. The Explorer might have been a bit quicker on the highway, but only a bit. Honestly, I really doubt I could tell the difference if I could drive the two back to back now. I know some doubt the benefits of the K&N aircharger but I do feel it helps the engine breath, assisting in countering any highway speed issues. It also seems to be assisted by lower viscosity synthetics that are designed to reduce friction and heat . In fact, when the H3 engine kicks in at high RPMs, I make sure I am hanging on because it "goes".
This whole horespower issue also is discredited by comparing the HP numbers of the Explorer vs. H3. And there is so much more torq...
Albeit one example of qualitative results as compared to quantitatie, dyno-type results, I have to say that this H3 set up is probably the most optimal. But again, that is my humble opinion.
It isn't a Mustang or for fair comparison's sake, a GM Cyclone, but it is a very, very good all around vehicle. For me, if I want wicked speed, I'll go home and pull the Probe GT out of the garage.
And I can agree with the statement on side-hilling the Xterra or even the Explorers (latter from experience) - keep in mind the horsepower issues
when you are barrel-rolling down those inclines
Oh yeah - and good luck with the Lemon Law - from experience, it is a joke.