For its introductory model year the Challenger was available in two series, Challenger and Challenger R/T, and three models, two-door hardtop, Special Edition two-door hardtop, or convertible. The base model was the Challenger with either an inline-6 or V8 engine. The Special Edition hardtop, available on either the base Challenger or on the R/T, added a number of appearance, convenience, and comfort features. Produced for the 1970 model year only, this more luxurious SE specification included as standard a vinyl roof with a "SE" medallions on the pillars, a smaller "formal" rear window, leather and vinyl bucket seats, and an overhead interior console that contained three warning lights (door ajar, low fuel, and seatbelts). The standard engine on the base model was a Straight-6. The standard engine on the higher trim models was a V8 with a 2-barrel carburetor. For 1970, the optional engines included the , as well as the V8s, all with a standard 3-speed manual transmission, except for the 383 cu in. engine, which was available only with the TorqueFlite automatic transmission. A 4-speed manual was optional on all engines except the Inline-6 and the 2-barrel V8.