Halloween names and colors - scary power. The bright orange Dodge Viper with a 645 horsepower 8.4-liter, overhead-valve, 20-valve, SFI, all-aluminum V-10 engine mated to a six-speed manual transmission and a top speed of 206 mph. Behind the Viper is the Halloween green 2015 Dodge Charger SRT Hellcat with a supercharged 6.2-liter HEMI® Hellcat engine, producing 707 horsepower and 650 lb.-ft. of torque, bragging to be the quickest, fastest and most powerful sedan in the world.