The Jeep Wrangler has never been limited by much; few terrains on Earth haven't seen the underside of a Wrangler's chassis. About the only thing that's ever limited the Wrangler's fun appeal has been how many people it could comfortably ferry to adventure -- and that's a problem that Jeep solved when it introduced the extended-wheelbase, four-door Unlimited version of its trademark trail buggy.
Whether in two-door base form or four-door Unlimited trim, the Wrangler still uses the same 202-horsepower, 3.8-liter V-6 engine. Jeep's parent company Chrysler specifies 5W-20 oil meeting Chrysler Material Standard MS-6395. That means any standard oil will work, but synthetic or a quality synthetic blend is approved and suggested to extend engine longevity. When you change the oil every 6,000 miles as Chrysler recommends, refill it with 6 quarts of the suggested oil. Remember to rotate your tires with every oil change, and inspect your brake pads, and engine and cabin air filters during every other oil change.