Nine 4Runner trims are available for 2021: the base SR5, Trail Special Edition, SR5 Premium, TRD Off-Road, TRD Off-Road Premium, TRD Pro, Nightshade, Limited and Venture. The engine on all trims is a 4.0L V6 making an impressive 270 horsepower and 278 pound-feet of torque. The standard transmission is a 5-speed automatic. The SR5 and Limited can get either rear-wheel drive or 4-wheel drive (part-time on the SR5, full-time on the Limited). Standard safety features include antilock 4-wheel disc brakes with brake assist, stability control, traction control, anti-skid system, active front head restraints, front knee airbags, front-seat side airbags and full-length roll-sensing side curtain airbags. Toyota's A-TRAC system is standard on all 4-wheel-drive trims, which can distribute driving force to any one wheel in contact with the ground, making rough driving much smoother. Four-wheel-drive trims also get standard Downhill Assist Control. Trail trims also get Toyota's Crawl Control, which regulates the vehicle's speed in severe off-road conditions and Toyota's Multi-Terrain Select system, which allows drivers to manually adjust the 4-wheel drive hardware to suit their needs. All 4Runner trims come with Hill-start Assist Control (HAC), which provides additional control by keeping the vehicle stationary while starting on a steep incline or unstable surface. The Limited trim comes standard with an X-REAS suspension system that automatically adjusts the damping force of shocks when driving over uneven surfaces or cornering. The Kinetic Dynamic Suspension System (KDSS) is available as an option, which can disconnect the front and rear stabilizer bars at speeds below 40 mph for greater wheel articulation. A system designed to prevent accidental acceleration by cutting throttle when both the accelerator and brake are pressed simultaneously is standard across the all trims. Standard equipment on the SR5 includes 17-inch alloy wheels, LED fog lights, air-conditioning, cruise control, full power accessories, a tilt-and-telescoping steering wheel and trip computer. SR5 premium trims with 4-wheel drive also get heated side mirrors with turn indicators and puddle lights, chrome roof rails and grille and a tow hitch receiver. All trims, including the SR5, come with Toyota's Entune audio system with smartphone integration, including navigation. The Limited trim adds a power sunroof, leather seats, an auto-dimming rearview mirror and integrated navigation system. The TRD Off-Road trim adds a hood scoop, a locking rear differential, Crawl Control, smoked taillights, power-adjustable front seats and a sliding rear cargo deck and is only available with a four-wheel drive powertrain. The TRD Pro Series Edition adds serious off-roading equipment, including TRD off-road springs and Fox shocks, Nitto Terra Grappler tires and a front skid plate. It also comes with 17-inch black alloy wheels and a unique front grill. The Limited trim adds 20-inch alloy wheels, Toyota's X-REAS adaptive suspension dampers, keyless entry and ignition, automatic headlights, dual climate control, an upgraded JBL audio system with navigation, a 8-inch touchscreen display and backup camera. A leather-wrapped steering wheel, leather upholstery, heated and ventilated front seats, power-adjustable front seats, Smart Key proximity entry and mirror and seat settings memory are also included. Nightshade Editions, meanwhile feature blacked-out exterior coloring, including the bumpers, mirrors, door handles, and more.