ToolManTimTaylor

Prolly a repost I am sure but:

From the October, 2011 issue of Motor Trend
By Allyson Harwood


Read more:
h t t p://www.motortrend.com/roadtests/suvs/1110_2012_jeep_wrangler_first_test/



You can't tell by looking at it, but the Jeep Wrangler has undergone a transformation. The iconic shape remains -- seven-slot grille, round headlights, short wheelbase, soft or hard top -- but Jeep has made huge improvements to the off-roader for 2012. Jeep invited us to drive the 2012 Wrangler on the Rubicon, one of the hardest 4x4 trails around, used almost exclusively by modified vehicles. We also got to drive on the two-lane asphalt roads that wind around Lake Tahoe.

Consider this the second part of a major overhaul to the Wrangler and four-door Wrangler Unlimited. Part one happened for the 2011 model year, when the JK (the current generation's code name) received a new interior, plus, on the Sahara, a body-color hard top and fender flares. The hard top is of the same composite material as it was before, but what sounds like a minor change actually has a major effect on the Wrangler's appearance. In addition, the rear windows are larger as of 2011, improving visibility. For 2012, the body-color hard top and fender flares are optional on the Rubicon, too.


Inside, welcome 2011 revisions include the use of higher-quality materials; the redesigned center stack; an all-new instrument panel; and strategically applied sound insulation that makes this the quietest Wrangler ever. Some creature comforts never seen here before -- seat heaters, power heated mirrors, and redundant steering wheel controls -- make this the most refined Wrangler cabin ever.


For part two: Prior to the 2012 model year, Jeep knew the Wrangler would get the Pentastar engine, even if the company didn't make an official announcement. The pairing makes perfect sense: more horsepower, more torque, and better fuel economy. The previous iron-block 3.8-liter V-6 put out 202 horsepower and 237 lb-ft; the all-aluminum Pentastar has 285 horses and 260 lb-ft. And, while the six-speed manual returns unchanged, the four-speed automatic has been ditched in favor of the Grand Cherokee's five-speed. All the rest of the major mechanical features (axles, suspension, steering, brakes), the body, dimensions, and structure are essentially carryover.



We started out on-road, driving to the Loon Lake trailhead from Squaw Valley, in the Sierra Nevadas. The route included elevation changes and sudden large openings in traffic that gave us opportunities to test out the Pentastar's acceleration. While this combination would've highlighted the weaknesses of the previous engine (universally considered a dog), the 3.6-liter V-6 shone.


The new engine offers excellent response and a noticeable improvement in power -- the Pentastar is significantly faster from a stop and when passing. Also, the engine sounds much more upscale than the coarse 3.8-liter, and the exhaust note is throatier. Paired with either transmission, it feels much more refined. Where the 3.8 feels pokey, the 3.6-liter actually makes the JK feel spry. Jeep estimates that the new engine reduces 0-60 times by 2-3 seconds with either transmission, and when we took a Wrangler Sport manual to the track, we confirmed this estimate. The new Jeep hit 60 mph in 6.7 seconds, while all of the 3.8-liter Wranglers took between 9.8 and 10.2 seconds.



When we reached the Rubicon trailhead, we swapped the Unlimited Sahara we'd been driving and got into a Wrangler Rubicon. The trail is in one of the most beautiful parts of the country. It cuts through an evergreen forest and runs up and over the Sierras. The terrain varies from slick granite to dirt dotted with rocks to massive boulders that require highly technical driving to traverse or go around. The trail takes you past breathtakingly beautiful vistas overlooking crystal-clear lakes. There was also more water on the trail than in the past, thanks to the heavy winter. Puddles appeared at the most inopportune times, and there were water crossings in spots where the trail had been dry the year before. The trail is known for changing year to year, but the conditions were especially tough this time around.

Despite the challenges, all the Jeeps survived. The new engine and trans worked well, and even though peak torque is now at a higher rpm, there was no noticeable difference when off-roading at low speeds.
Jeep's goal with this latest version of the Wrangler is to make the vehicle more refined and better on a day-to-day basis, without sacrificing the JK's off-road ability. The new Wrangler stays true to the model's roots, but now it's a lot more fun to drive on-road.


The Lowdown
Talk about the two-year upgrades to the Wrangler.
Ray Durham, Vehicle line executive
The two-step evolution of the model gave us more time for the Pentastar development. Engine development was happening at the same time as the interior changes, allowing the engine to be ready to go in a short amount of time.
What did it take to ready the Pentastar for the off-road requirements of the Wrangler?

Tony Petit, Responsible for the Wrangler and Liberty
We had to create a unique oil pan, an acoustic engine cover to reduce noise and improve appearance, optimized upper intake airflow for torque, and add equal-length downpipes to improve low- and mid-range torque response. Also unique are the front-end accessory drive and high-mounted rear-facing alternator for water fording. Its new pulse-width modulated 600-watt fan is 100-percent variable speed, not just high and low, plus it has a full face condenser for better A/C performance and a standalone transmission oil cooler.

MagnumD69

What a great picture. I'm usually a "red vehicle" kind of guy, but that Yellow is growing on me.

Noxian

Well that settles it,

Like it or not the 3.6 is better on the road. However as they say

So I guess if you wheel your 3.8 you wont be missing out

jhol111964

Just think how much faster it would be if it were red!

WXman

So they didn't mention the quality control issues in the mexican engine plant? Word on the street is that they are scrapping up to 2,000 blocks per week on the engine line... they are getting crappy parts from suppliers and overall quality is suffering. Jeep is trying to weed out the problems and only allow quality out the door... but I don't want a new 3.6 for sure. Give it a few years... then double check the window sticker for an american engine before buying.

Everybody is flying to the 285 horsepower number like flies to a flourescent light...but nobody is thinking about the PITA it's going to be to work on that engine in the driveway, the quality longterm, etc. etc...

panthermark

The new engine if only 50% of the benefit.

If you want an auto, the new 5-speed (which much improved gearing) is a huge improvement. Besides, pretty much every car is becoming harder to work on.

Fenrir

Can you cite your source about scrapping 2K blocks /week?

dlborda

Final assembly: OH
Engine: US
Tranny: DE

No bugs so far!

181

LOL By "on the street" do you mean "in my head". And we all know the 3.8 has been a pillar of durabilty amongst domestic engines. Yes, kindly ingnore the "My engine is doing _______" threads that seem to pop up daily on here. BTW Edmunds only rates Corvette engine & powertrain reliability a 2.5 out of 5, so maybe your fellow Kentuckians can learn a thing or two from our friends south of the border about engine assembly.

Noxian

Sounds like the OP is taking things abit out of context, See the link below, it suggests that they are having casting problems with the blocks made in mexico, not completed engines, and no numbers from confirmed sources are quoted. At the time of the post "January 24, 2011" it indicates there are shortages at the Trenton plant because of this.