Dodge spent months teasing the 2018 Challenger SRT Demon without showing a single performance number, leaning instead on the idea that cold, dense air is what really makes a muscle car. When the specs finally landed, they made the teasing look modest: 840 horsepower, a 9.65-second quarter mile, a factory transbrake, an air conditioner repurposed to chill the intake, and a Guinness record for lifting the front wheels off the ground.