Readers may remember that I was underwhelmed when I first drove a vehicle with the Pentastar 3.6L VVT V-6 that everyone else was gushing about. Now that I’ve spent some time driving a 2012 Wrangler with the 3.6L and the A580 five-speed automatic transmission, I’m eating my words.
The 2012 JK Wrangler Unlimited Rubicon is a great improvement over earlier models. The 3.6L VVT V-6 produces 80 more horsepower than the 3.8L V-6 it replaces, but does so at high rpm. The 2012’s low-end performance is better than earlier JKs, though. The real star, I suspect, is the A580 automatic.
The transmission is a gem. With a 3.59:1 first gear, 2.19 2nd, 1.41 3rd, 1.0 4th, and 0.83 overdrive 5th (Reverse is 3.16), the new Wrangler never has a problem finding the right gear. Manual shifting is easy. With the selector in D, the shifter is rocked side to side to shift down (or back up). The A580 is so strong it’s also used in trucks and Hemi-equipped vehicles.
The 3.6L’s relative lack of low-end torque is overcome with the automatic’s low 3.59 first gear. Ledge climbing and crawling is accomplished without a whimper.
If you’re in the market for a 4x4, the 2012 JK Wrangler is worth a look.
The aluminum block Pentastar...
The aluminum block Pentastar 3.6L VVT V-6 delivers 285 horsepower at 6,400 rpm and 260 lb-ft of torque at 4,800 rpm. It’s a great improvement over the old 3.8L V-6 and, yes, the 4.0L straight-six. In our testing, we saw between 15 and 22 mpg. Popping off the engine cover reveals an easily-accessed paper element oil filter up top for easy oil changes.
Originally designed to work...
Originally designed to work behind Hemi V-8s, the fully electronic A580 five-speed automatic transmission features a low 3.59:1 first gear, 2.19 2nd, 1.41 3rd, 1.0 4th, and 0.83 overdrive 5th (Reverse is 3.16). The new Wrangler never has a problem finding the right gear. Selecting the right gear is easy, too. Put the selector in D, and then rock it side to side to access the gear you want. Designed for “fill for life,” Jeep says the transmission requires no maintenance under normal operation. We’ll see about that, but we can report that the A580 automatic works well behind the 3.6L V-6 and allows the new JK to crawl with the best. Of course, the NVG241OR Rock-Trac transfer case in the Rubicon helps crawling with its 4:1 low range ratio.
A lot of work went into the...
A lot of work went into the 3.6L’s exhaust. Equal length runners were required for maximum performance, hence the loop on the driver’s side. As this was the only exhaust part that wasn’t replaced on our well-used press mule, it doesn’t hang down as much as we thought it did.
The exhaust crosses over beneath...
The exhaust crosses over beneath the transmission and can be hit by the driveshaft when increased height suspension systems are installed. An easy fix would be to extend the pipes back and cross over where the tranny and transfer case meet. There’s even room for the pipe!
The 2012 has a new midship...
The 2012 has a new midship muffler as well as the muffler in back. Note the new OE skid plate for the vapor canister.
This little vacuum pump is...
This little vacuum pump is mounted behind the front bumper. It provides a challenge for aftermarket bumper installations. There are already a couple of solutions available for moving the pump into the engine compartment.
Rear seats fold down almost...
Rear seats fold down almost flat. Slip a foam insert in to fill the gap and people could sleep in the back of the Unlimited.
The JK’s Dana 44 rearend is...
The JK’s Dana 44 rearend is strong and reliable. Unfortunately, the Rubicon’s front 44 remains unchanged and needs upgrading.
No more slamming tailgates....
No more slamming tailgates. The tailgate features an internal stop that holds the gate open, even when the Jeep is parked on a sidehill.
The subwoofer is in a bigger...
The subwoofer is in a bigger enclosure for more bass. Note the 12-volt power outlet.
The 2011 interior upgrades...
The 2011 interior upgrades continue into 2012. Interior comfort is superb.