The base version of Mercedes' American-built SUV gets a mid-2003-model-year upgrade with a larger V6 engine. The new V6 ML350 with a 232-hp 3.7-liter V6 replaces the ML320 with its 215-hp 3.2 V6. The V8 ML500 and high-performance V8 ML55 AMG continue. All have a 5-speed automatic transmission with manual shift gate, all-wheel drive with low-range gearing, antilock 4-wheel disc brakes, and an antiskid/traction-control system. Also standard are front and rear torso side airbags and head-protecting curtain side airbags. Mercedes' TeleAid assistance system and dashboard screen for controlling audio and navigation systems is also included. For '03, the navigation system switches from a CD to a DVD-based setup that requires fewer discs; it's a dealer-installed option for the ML350 and standard for other models, and Mercedes says it can be retrofitted to 2000-2001 models. Leather upholstery is standard on V8 models, optional for the ML350. A 2-person 3rd-row seat is available except on the ML55. The ML55 comes with 18-inch wheels vs. the other models' 17s, plus functional and appearance upgrades by Mercedes' AMG performance team.