Having come from a performance car back ground with an in house chassis dyno i'll always be a fan of air intakes with a velocity stack(K&N for the jeep) and exhaust systems. my wife has a 2007 JK with just a K&N intake,when we bought the jeep average mpg was 19 on the jeep cluster and 19.2 on my calculator, that was a strip from Pittsburgh to columbus ohio via rt 70. after the intake almost the same trip from Pittsburgh to Logan Ohio 21.7 on the jeep cluster and 21.9 on my calculator(also via rt 70). around town we dont pay to much attention with since she only works 8 miles away and its alot of stop and go traffic and red lights.
On the dyno i never seen a vehicle lose hp with a velocity stack equipped air intake, but i seen gains as low as 1hp and gains as high as 12hp(this was at the wheels). so for the price id give that a shot.these are figures i have seen so thats my suggestion, everything else is down to weight and aerodynamics.
Im very interested in your trip also, as soon as i get my 2nd week of vacation from work my wife and I would like to take a 2 week trip just as you have planned but were still mapping out routes and sites. we'll most likely be taking my TJ instead of her JK.
2002 Jeep Wrangler
2007 Jeep Wrangler
You have to be lost to find a place that can't be found, elseways everyone would know where it was.