Because stock for stock it'll tear the ass out of a Fox Mustang.
I would know... but I was on 35s with half a ton of armor.
In all fairness, the 5.0 sounded pretty ragged out.
Really, though, I was referring to the older TJs. They're ~3500 pounds in stock form. Usually add about 1,000 pounds for armor, upgrades, and tires. Can't imagine Explorers are 4,500... when Crown Victoria station wagons with 5.0s and AODs are only 4,100.
But yes, the JKUs are heavy as balls. Still, all armored up and lifted on 35s, I can drive three hours (200 miles) to our "local" off-road park, wheel all weekend, and make it within 30 miles of driving back before I need to get gas again... on a 22-gal tank. That's no exaggeration, I've done it every time. Next time I want to see if I can get all the way home without stopping for gas.