Although the 2000 Impala was supposed to replace it, Lumina lives on as a less expensive midsize Chevrolet sedan aimed mainly at the fleet market. Last redesigned for 1995, the Lumina now comes in one model versus three, equipped between last year's base and LS offerings. That means a 3.1-liter V6--newly retuned for 15 extra horsepower--plus standard automatic transmission, cruise control, air conditioning, power windows and mirrors, and AM/FM/cassette stereo with automatic loudness adjustment. Options include front bucket seats in place of the standard 60/40 bench, and an Appearance Package comprising upgraded cloth upholstery, AM/FM/CD audio, 16-inch aluminum wheels with higher-performance touring tires, and antilock brakes. GM's OnStar communications system remains available.