The 4.0 litre Inline-6 is what my dads Jeep has, it has a K&N Filter, and Jet Performance Stage 2 chip upgrade, he wants to put a Borla exhaust on next. He pulls a 16 foot double axel trailer with it, with a 2002 Honda Goldwing 1800 and a bunch of other stuff inside, it gets up hills so good.. lots of power from that straight 6, even without the performance upgrades, it pulled the trailer plenty fine.
imo I think Jeep makes the only true SUV on the market still. none of this luxury crap thats all looks and no game, or this crap they call SUV's but uses a car chassis.