Test Drive: 2021 Jeep Wrangler Unlimited Rubicon 392
For decades, Jeep fans have yearned for a factory-produced Wrangler loaded with a V8 under the hood. They have pleaded on message boards, begged Jeep on its social media accounts and even written letters to Jeep executives. The answer? It was always—“No”.
The last time a V8 was available in one of the Wrangler’s descendants was in the 1981 CJ-7. And it made those models quite a lot of fun. But even in its best years, the AMC 304 V8 delivered just 150 hp at 4,200 rpm and 245 lb-ft of torque at 2,500 rpm. Back then, those weren’t bad numbers. The 304 V8 may have left the line in the early 1980s, but juicy rumors and a desire for eight pistons remained.
When Jeep began to install V8s in the Grand Cherokee, many wondered if the Wrangler would be next. And it came tantalizingly close to happening in the late 1990s—sort of. A rogue group of Jeep engineers were quietly building and testing prototypes of a “super duty” off-road package in the Wrangler. These mules, which would later become the production TJ Rubicon, were fitted with locking differentials inside Dana 44 axles and ultra-low gearing in the transfer cases. To find out if these parts would break or survive on the trail, Jeep actually built a few prototypes with V8 engines. The thinking was, if the torque a V8 TJ can’t break them, a straight-six certainly won’t. After hearing the V8 exhaust sounds in these test vehicles, spy photographers incorrectly assumed that a V8 Wrangler was on the way. Magazines printed the news and waited. Of course, the V8 never came but the Rubicon made up for it.
In the 1990s a V8 would have transformed the performance of the Wrangler. But do we really need a V8 today? After all, a 2.0-liter turbo four-cylinder Rubicon can hit 60 mph in about 7.5 seconds. That’s not slow. Yet Wrangler fans have never stopped asking for eight cylinders. And there’s nothing quite like the instantaneous thrust of a hot-blooded V8. So in a surprise move, Jeep announced they would be building a special V8 Wrangler. Since the performance of normal Wranglers is so good, Jeep knew they had to go big with a V8 model. So instead of the 5.7-liter Hemi V8 which develops 360 hp in the Grand Cherokee, Jeep pulled the SRT-grade 6.4-liter V8 (392 cu-in) from its arsenal with 470 hp and 470 lb-ft of torque. Hoofa.
We had a chance to spend a few days with this amazing machine recently. Take a deep breath, because at an as-tested price of $78,545, our Snazzberry Pearl Coat Wrangler 392 is wildly expensive. In fact, that’s about $35,000 over the base price for a Rubicon. To be fair, the MSRP for Rubicons can drift slightly north of $60,000. But nearly 80-grand for a Wrangler is a lot. So, is the V8 pleasure worth that financial pain? To find out we piled some miles on the 392 and spent a day with it blasting around Hungry Valley SVRA in Gorman, CA. We had big expectations. So, let’s find out if this Jeep delivered the thrills.
The basic Wrangler 392 does not stray dramatically from the four-cylinder and V6 Rubicons. Under the hood of course is the SRT-built 6.4-liter V8. To fit the new motor, Jeep had to employ new motor mounts and fashion a new crossmember that would clear the V8’s crank pulley. The big V8 produces 470 hp at 6,000 rpm and 470 lb-ft of torque at 4,300 rpm. Jeep says that 75 percent of the torque is available at just off idle.
The 392 can ford water crossings 32.5-inches deep. A high-mounted alternator helps with that as does the new Hydro-Guide air intake. The new intake uses the hood scoop from the Gladiator Mojave and incorporates a tri-level ducting system with drains (including a one-way drain in the airbox) that can handle 15 gallons-per-minute of water over the hood. This will allow the 392 to take on water crossings and probably become the best-performing mud Jeep the company has ever produced.
If that bodacious scoop happens to get blocked by a clump of dirt or packed in with snow, there’s a secondary air path that becomes active to feed the big V8. Smart. And this Hydro-Guide system is certainly stout because when you lift the hood of a 392—you will feel the added weight. It’s heavy. To keep the engine cool on hot days, there’s an upgraded cooling fan as well as the freer-flowing Gladiator grill up front.
This is one Jeep that’s proud to let everyone know there’s something special under the hood. Just press the exhaust button on the dash. The pipes uncork and makes the Jeep sound like something that belongs at a drag strip. Thankfully another press of the button keeps the exhaust V6 quiet so you can remain a bit stealthier (and refrain from annoying your neighbors).
An 8-speed automatic is the only gearbox choice and it’s well-matched to the 392. And it has a manual mode to provide a bit more control over the motor. The 392 is unlike other Rubicons because in place of the 4:1 transfer case is the Selec-Trac unit from the Sahara. This not only provides full-time all-wheel drive (sadly there’s no 2WD mode) but 4 High as well as a 2.72:1 geared low range. Jeep says the V8’s torque makes transfer case gears any lower unnecessary. And while that’s likely true, our hunch is that it also saves the axles from a bit too much torque multiplication.
The Rubicon 392 engineering team considered Dana 60 axles for this Jeep. However, they were limited on space underneath and so the choice was made to upgrade the Rubicon’s Dana 44s. In fact, the axles are similar to the units found in the Gladiator Mojave. The front axle has cast iron knuckles and thicker axle tubes. There are axle CV axle shafts instead of traditional U-joints because the rig runs all-wheel drive—all the time.
Out back, the rear axles have thicker tubes as wells as reinforced and revised mounting points for improved handling. There’s a stiffer rear swaybar too. Both axles have 3.73:1 gears and electronic locking differentials. To help clear the engine, cooling system and some of the drivetrain components, the suspension has a one-inch lift over a standard Rubicon with re-tuned Fox 2.0 monotube dampers. The BF Goodrich All-Terrain tire size remains at 285/70R17.
The Rubicon 392 weighs in at 5,103 lbs. That’s 241 lbs. more than an Ecodiesel Wrangler. And every Rubicon 392 has a payload of 850 lbs. Thanks to all the cooling work, Jeep has maintained the 3500 lb. towing capacity as well.
On the Street
The sweet Snazzberry paint and the subtle bronze accents really make this Rubicon a stunner. And the slightly taller stance as well as that massive hood scoop make the 392 both menacing and very appealing. This is one tough-looking Jeep. And that’s especially true when you catch sight of the quad tipped exhaust pipes tucked up behind the rear bumper.
Slide inside and there’s a full leather interior and subtle bonze stitching. The seats are more highly bolstered than a standard Rubicon and come from the Mojave. And when you wrap your hands around the steering wheel it’s evident that it has a thicker rim. It too comes from the Mojave. And to help control the 392, there are paddle shifters. The rest of the interior would be a familiar place for any JL owner. This was our first experience with the Sky One-Touch power soft top. It’s a $2,000 option that essentially has a power fabric center roof section combined with the hard doors and hard side windows. It’s a great way to experience open air fun without the hassle of messing with a softop or removing a full hardtop.
The moment you press the start button on the dash and the big V8 fires to life—you know some serious fun is about to happen. The 392 Rubicon is as close as you’ll ever get to having a Jeep bodied muscle car. This thing is ridiculously quick. And it sounds amazing too. The whole experience almost feels like it was cooked-up by the aftermarket or a tuner shop because your brain can’t imagine Jeep greenlit a vehicle this bonkers.
The power and torque of the 6.4-liter V8 change the way the Wrangler feels in every situation. And that’s because you can simply carry so much more speed. After all, Jeep says it will hit 60 mph in just 4.5 seconds. For that reason, the suspension feels a little soft and rolls in the corners more than we’d like. Similarly, there’s a vagueness to the steering. And in a vehicle that’s this potent, precise steering would be welcome. Perhaps the worst offender in the drivetrain is the brakes. The pedal feels soft and they simply don’t supply enough braking force to slow the 392 when you’re really working it hard. If it were our Jeep? We’d at least swap in some better brake pads or even upgrade to a full brake system, like Mopar’s Big Brake Kit. Still, this Jeep is just so much fun on the street your brain will let most of those criticisms slide.
On the highway, the Rubicon 392 can reel-in just about anything it wants. Just stand on the throttle and the Jeep accelerates hard. We chased a new Mustang GT up a steep freeway grade and caught it. Hills are effortless in this beast. It’s insane fun on any road. But if you use all that power and speed be ready for some poor fuel economy. The EPA rates the Wrangler Rubicon 392 at 13 mpg city and 17 mpg on the highway. In our mixed driving, which included quite a lot of hard acceleration, we averaged 12.4 mpg. Not great but we were honestly expecting worse.
On the Trail
Pull off the pavement onto a moderate trail and you won’t need to pull a lever or push a button for a while. Even without the diffs locked, the transfer case in low range or even locked in 4 High, and the swaybar disconnected—the Rubicon 392 easily cruises up and over some fairly challenging obstacles. It’s a beast.
We measured 10.3 inches of ground clearance and Jeep says the 392 has an approach angle of 44.5 degrees, a departure angle of 37.5 degrees and a breakover angle of 22.6 degrees. Nothing else on the market right now comes close to those numbers.
So, we went straight to the deep mogul section of the park to see if the torque of the V8 was enough for the Jeep to tackle that uphill axle twisting section in high range with no axles locked and no swaybar disconnected. Success. It wasn’t pretty and the traction control was working hard but this is the first 4X4 we’ve ever tested to make the climb using open diffs without low range. Very impressive. Once we added in all the rest of the trail tools, the section was completed without so much as one tire slip.
On our rough hill climbs, the power of the V8 made short work of any challenges. This Jeep is a hill climbing champ. Dig into the throttle in low range and the soft sandy soil flies sky-high. The only hill to stop us was one that was so rutted our front diff ran aground. But on any of the others where we could find a line—the 392 scampered right up. We can only imagine that this would be an excellent Midwest mud Jeep.
The Jeep was incredibly fun everywhere we took it. But in the sand, the Rubicon 392 simply ripped. In this terrain, the best mode is 4 High with the Rubicon 392’s Off Road Plus button pressed. This is a special mode first developed for the Gladiator Mojave. Think of it as a sport mode for higher-speed four-wheeling. The stability and traction control functions become less restrictive, the transmission holds onto a gear longer and the throttle mapping is adjusted. It also allows the rear diff to be locked in 4 High. And the settings really work. You can feed in a ton of throttle and the 392 puts the power down with just enough fish-tailing to make it really fun.
Similarly, the Rubicon 392 impressed on the rough dirt fire roads around the park. The motorcross bikes had turned our favorite section into a series of small whoops. The Jeep wasn’t as composed as say, a Gladiator Mojave, but at speeds around 25 mph it felt controlled. The real problem is the temptation under your right foot. When it comes to higher-speed four-wheeling, the Jeep has more motor than the suspension can handle. It’s very easy to be carrying way too much speed, as we found out more than once. It’s too much fun. Thankfully, we didn’t bend an axle. If this was our rig, we’d be tempted to upgrade the suspension with dampers better-suited to high-speed runs.
The Bottom Line
The Rubicon 392 is quite simply our favorite Wrangler currently on the market. The power is intoxicating and truly transforms the Wrangler into a super Jeep. It’s a muscle truck on the street and a torque monster on the trail.
Yes, it’s very expensive but to a certain segment of the Jeep world, this is the Wrangler to own and perhaps keep forever. So, if this Jeep even remotely appeals to you, get in line before they’re gone. This Wrangler is almost certainly destined to be a collectible 4X4 in the future.