The Wrangler is the cornerstone of the iconic Jeep brand. The vehicle's seven-slot grill is recognizable to even the most casual car enthusiast, and the vehicle's trademark open-tub, convertible, four-wheel drive platform has spurred many imitators, but never had a true equal in the marketplace. The 4.0-liter in-line six-cylinder engine that powered the majority of the Wrangler trim levels offered a torque-heavy engine well-suited for a capable, specially-built off-road machine like the TJ-bodied Wrangler.
The 4.0-liter, in-line six-cylinder engine was offered during the entire production run of the TJ-bodied Wrangler, spanning from the 1997 to the 2006 model years. The engine was officially called the AMC 242 engine from 1997 to 2001. This engine had a 12-valve pushrod design with a 3.88-inch bore, a 3.41-inch stroke and a compression ratio of 8.8-to-1. Output for the engine was rated at 181 horsepower at 4,600 rpm and 22 foot-pounds of torque at 2,800 rpm. The engine underwent minor power band tweaking that would increase its power from the 2001 model year onward. The motor was renamed the PowerTech to reflect these adjustments and produced 190 horsepower at 4,600 rpm and 235 foot-pounds of torque at 3,200 rpm.
The 4.0-liter, in-line six-cylinder engine was paired with multiple transmissions throughout the TJ-bodied Wrangler's production run. All trim levels and body styles offered a choice of automatic or manual transmission, but the gearing changed during the Wrangler's life cycle. Jeep offered a choice of a five-speed manual or a three-speed automatic from 1997 to 2002. Jeep dropped the three-speed automatic after 2002 and replaced it with a four-speed automatic transmission that was offered through 2006. The five-speed manual continued in production through 2004. The final two years of the TJ-bodied Wrangler featured a Mercedes-sourced six-speed as its manual transmission option.
The base-model Wrangler SE was never offered with the 4.0-liter straight-six engine, and derived its power exclusively from a four-cylinder engine. The 4.0-liter, in-line six powered the Sport and Sahara models starting with the TJ's introduction, in 1997. Toward the end of the TJ body's life cycle, more trim levels were introduced; all of them were powered by the 4.0-liter, in-line six-cylinder engine. These models included 2002's strip-model X, 2003's performance-oriented Rubicon, 2004's extended-wheelbase Unlimited and 2005's extended-wheelbase performance-minded Unlimited Rubicon.
All Wranglers built on the TJ chassis from 1997 to 2006 were two-door body styles with four-wheel drive. The introduction of the JK-bodied Wrangler in 2007 marked the first time that the Wrangler was offered with four doors or two-wheel drive systems, but these models were powered by a smaller displacement 3.8-liter engine with a different V-6 configuration. All 1997 to 2006 Jeep Wranglers were built on a 93.4-inch wheelbase, with an overall length of 154.9 inches, with the exception of those models bearing the Unlimited designation. The Unlimited and Unlimited Rubicon models sat on an extended 103.4-inch wheelbase, with an overall body length of 171 inches.
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