Jeep's rough-and-ready workhorse wagon for 2003 takes on an ultimate off-road edition called Rubicon. Named after the Rubicon Trail, treacherous 4WD route traversing California's High Sierras, Rubicon provides factory-installed equipment usually reserved for vehicles modified with after-market equipment. It uses Jeep's 4.0-liter in-line-six Power Tech engine with a manual five-speed or new four-speed automatic transmission and features a 4WD system with push-button convenience for driver-actuated locking differentials, front and rear Dana 44 axles, four-wheel disc brakes, Goodyear Wrangler MR/R tires on 16-inch wheels and plate sill guards. Jeep's new four-speed automatic transmission is also available on other Wrangler models, including SE, Sahara and Sport. Wrangler SE stocks as standard a new heavy-duty five-speed manual with synchronized reverse gear. Sahara comes with hard doors containing roll-up windows, while Sport has foglamps and tow hooks evident in front. Wrangler's base 2.5-liter four-cylinder engine has been replaced on 2003 models by a new 2.4-liter Power Tech four with 25 percent more power, now at 150 hp. Dark Khaki substitutes for Tan on a new three-ply Wrangler soft-top, with Dark Slate or Khaki for the cabin shade and four new tones showing up as options for the body tint, including Bright Silver Metallic and Inca Gold Pearl Coat.