How to Design & Engineer a Jeep Wrangler (Not That You Would)
While you could end up in court if you tried this, it is worth noting that there are some quintessential aspects that make a Jeep Wrangler—including the just introduced 2012 Wrangler and Wrangler Unlimited models—what they are and what they have been since the first Jeep in 1941. Well, that’s not entirely true: the 1941 MB had a nine-slot grille, and the first item on our list has a different number:
• Seven-slot grille. This has been used on Jeeps since 1945 (the first was the CJ-2A).
• Flat body panels. Compare Wrangler body sides with any other vehicle out there, even vehicles in what is possibly its competitive set (Toyota RAV4, Ford Escape, Honda CRV—although none of these vehicles has the capabilities of a Wrangler), and you’ll quickly see that whether it is the side view, plan view, or front view, those panels are awfully flat. The original reason for this approach was to provide quick coverage of the chassis. The original specs from the U.S. military for the “light reconnaissance vehicle” was for it to have a rectangular-shaped body.
• Trapezoidal fenders. Not only is this fender shape used on the Wrangler, but it is a design cue that can even be found on the Grand Cherokee (see autofieldguide.com/articles/the-2011-jeep-grand-cherokee-grace-capability-under-pressure%283%29; or Automotive Design & Production, Sept.-Oct. ’10).
• High approach and departure angles. The 2012 Wrangler has a 44.6° approach angle and a 40.6° departure angle. (It also has a high ground clearance: depending on tires and model, it can be as much as 10.6 in. from the front axle to ground and 10.3 in. rear axle to ground.)
• Two-speed transfer case. It has been using a two-speed transfer case since 1941. The first civilian Jeep, the 1945 CJ-2A, had a Spicer 18 transfer case. The 2012 Wrangler and Wrangler Unlimited use transfer cases (Command-Trac and Rock-Trac) produced by Magna Powertrain (magna.com). (The Wrangler, incidentally, is produced at the Toledo Supplier Park in Ohio.)
Let’s face it: Anyone who has ever seen a Wrangler can probably identify it as a Jeep.
When Brian Nielander, Jeep Exterior chief designer designer—a College for Creative Studies (collegeforcreativestudies.edu) grad, who has been with Chrysler since 1998 and has worked on projects including the ME 412 concept (2004), Firepower concept (2005), and Challenger production car (2008)—who has been in the Jeep studio for two years, talks about how the Wrangler is approached in that studio, he uses the word “religion.”
Maybe it is, as the phrase has it, “a Jeep thing,” but there is a reverence to the Jeep that’s unmatched by any other vehicle, something that borders on hard-core reverence.
Nielander acknowledges that the tendency of any designer is to want to change things, “The Wrangler is bigger than any designer.”
Fast Product Development Fact: The first testing prototype Jeep, the Willys Quad, was designed by Delmar G. Roos, vice president of Engineering at Willys-Overland. The vehicle was delivered to the U.S. Army in the summer of 1940 in 49 days.
More Power: The biggest change for the 2012 Wrangler as compared with the 2011 model, which underwent an extensive reworking of the interior, providing everything from soft-touch plastic surfaces to Uconnect infotainment systems, yet which still which permits the carpet to be pulled, plugs in the floor pan removed, and water to be drained should there be a need for a washout, is in the powertrain.
The Wrangler is being equipped with the 3.6-liter Pentastar V6 engine. The engine—produced at the Trenton South Engine Plant, Trenton, MI—provides 285 hp @ 6,400 rpm and 260 lb-ft of torque @ 4,800. Those are improvements of 40% and 10%, respectively. The Wrangler’s standard transmission is a six-speed manual. It is also available with a five-speed automatic.
The V6 and the five-speed are the same that are available in the Grand Cherokee.
While the Pentastar is available in a variety of non-Jeep vehicles—including the Chrysler 200 and 300 sedans, and Town & Country minivan—according to Ray Durham, vehicle line executive, Rear-wheel Drive SUVs, modifications had to be made to the engine, like repositioning the alternator and intake manifold.
That’s because unlike the aforementioned cars and minivan, the Wrangler offers water-fording capability: it can travel through 30 in. of water.
Don’t try that in anything other than a Jeep.
Nowadays in the U.S. market, vehicle manufacturers pretty much are all committed to producing crossover utility vehicles rather than their predecessor type, the sport utility vehicle.
A young(ish) guy that I’ve known for a number of years, a man who spent the better part of his career writing for auto buff books and who is a car racer on the side, mentioned to me that his wife has a used Lexus ES Hybrid.
By James Gaffney, Product Engineer, Precision Grinding and Patrick D. Redington, Manager, Precision Grinding Business Unit, Norton Company (Worcester, MA)