For 2021 the Toyota Tundra is offered is six trim levels; SR, SR5, Limited, Platinum, 1794 Edition and TRD Pro. Additionally, the Tundra is available in many configurations to meet different truck owners' needs, with two- or 4-wheel drive, three cab styles (regular, Double Cab and CrewMax), three bed lengths, three wheelbases and two different V8 engines. A 5.7L i-FORCE V8 makes 381 horsepower and 401 pound-feet of torque and is standard on all models along with a 6-speed automatic transmissions. The Tundra is available in a rear-wheel drive with a limited-slip differential, or 4-wheel drive with an electronically controlled transfer case and limited-slip differential. Regular cab models offer the standard 2-door arrangement with one row of seating. The Double Cab offers smaller rear doors for occasional back-seat passengers, and the big CrewMax brings full-size rear doors and seating comparable to that offered in big SUVs. CrewMax models also have a unique reclining and sliding rear seat, while Double Cabs get a folding seat bottom that allows for a flat storage area when the seat isn't in use. Three bed sizes are available depending on the model Tundra chosen; 5.5-foot short bed, 6.5-foot standard bed or 8.1-foot long bed. Each of the three beds is about 22 inches deep and shaped to accept 2x8-foot lumber dividers. The steel tailgate is designed to be opened and closed with just two fingers, and there's also an available Deck Rail system for more individualized cargo arrangements. All Tundras have a rear suspension design that keeps the rear deck level even with a full load, fully boxed frame rails and rolled C-channel members underpin the truck. All Tundras come with a tow hitch receiver and when properly equipped, is rated to tow nearly 11,000 pounds. The Tundra ranges from basic to very luxurious inside depending on the trim level, starting at the spartan SR model and going all the way up to the very well-appointed Limited or TRD Pro. Inside, all models feature a tilt/telescopic steering wheel, door handles and control knobs large enough to be operated with gloves. The glovebox is designed to be big enough to hold a Thermos and the center console is large enough for a laptop or for file storage. Interior power outlets stay live for two hours after the ignition is switched off. The no-frills SR trim level is available in standard cab or double cab versions. It features 18-inch wheels, black bumpers, LED running lights, fabric seats, rubber floor mat and heated power-adjustable mirrors, Entune audio and a rearview camera. The SR5 trims get an upgraded Entune audio system with SIRIUS satellite radio and Bluetooth, chrome bumpers and grille surround, power sliding rear window and fog lights. Available options include an off-road package, tow hitch and integrated navigation. Limited Double Cab and CrewMax get equipment upgrades such as 20-inch aluminum wheels, dual-zone automatic climate control, leather-trimmed seats, heated power front seats, LED headlights and fog lights, 38-gallon fuel tank, tow package with integrated trailer brake controller and integrated navigation. The Platinum Tundra trim includes 20-inch alloy wheels, brushed-metal style exterior trim, a memory-enabled driver's seat, power sunroof, turn signals integrated into the mirrors, an upgraded premium JBL stereo, heated and cooled front seats, dual-zone climate control, a navigation system and a metal-appearance interior. The unique 1794 Edition has similar features of the Platinum, but updates the interior styling with brown leather seating and wood accents. On the exterior, a unique chrome billet-style grille is included. For those looking for enhanced off-road performance, Toyota offers the TRD Pro trim, which comes with 18-inch BBS forged aluminum black wheels, TRD-tuned Fox suspension, an aluminum skid plate, tuned dual exhaust, Rigid Industries fog lights, a unique grille and TRD Pro leather seats. The Trail Edition adds 18-inch silver alloy wheels, fabric seat trim with Trail Edition, 1794 grade grille with color surround, black badging and all-weather floor mats. The Nightshade Special Edition comes with 20-inch black alloy wheels, a black exhaust tip and diffuser, heated power mirrors with black caps, black badging and black wheel locks. The Tundra offers a very comprehensive set of standard safety features. Front-seat side airbags are standard on all models, along with roll-sensing side-curtain airbags and a front seat knee airbags. Four-wheel disc brakes with vehicle stability control are standard on all Tundras. The Tundra also features standard trailer sway control programming and brake override technology. It utilizes the truck's stability control system to detect unintended side-to-side movement at the rear wheels. Should the system detect movement, the truck's anti-lock brake system is used to counteract yaw and prevent jack-knifing. A trailer brake controller allows the driver to control the amount of brake boost applied to the trailer's electric brakes when the driver applies the vehicle's brakes.