3.8-liter V8s are common in many of McLaren's products, but the 720S gets a special 4.0-liter twin-turbo V8. This power plant produces 720 British horsepower, hence the name. In our money, that's 710 hp with 568 lb-ft of torque. A seven-speed dual-clutch automatic controls gear shifts, and it's just as impressive as the engine. Shifts are smooth and sharp, with barely a few milliseconds interrupting the flow of power. Thanks to clever turbo engineering, the 720S is almost completely free of turbo lag. Throttle response is near-instant and the revs keep climbing effortlessly, with a wave of constant power shoving you in the back and making you open your eyes involuntarily wide. From the line, a launch control system helps those turbos spool up to optimum levels, and when you let go of the brake pedal, you jump ahead with the kind of vicious acceleration that is sure to elicit fear from your unsuspecting passenger. That power is always available, and overtaking opportunities that would normally seem insane are now dealt with in record time. The notchy click of the steering-mounted paddles is also satisfying, encouraging you to engage with the car and row up and down the gears at every opportunity.