Toyota's Tundra is available in many variations to meet different truck users' needs for 2013, with 2- or 4-wheel drive, three cab styles (regular, Double Cab and Crew Max), three bed lengths (short, standard and long), three wheelbases and three different engines. The 5.7L V8 offers an E85 flex-fuel option. 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. Regular cab models are 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 Crew Max brings full-size rear doors and seating comparable to that offered in big SUVs. Crew Max 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. The base engine on regular and Double Cab standard-bed models is a 236-horsepower, 4.0L V6. Crew Max and Double Cab long-bed models get a 4.6L V8 making 310 horsepower and 327 ft-lb of torque. A 5.7L "iForce" V8 making 381 horsepower and 401 lb-ft of torque is available on all models and in some regions, the engine can be optioned to run on E85 ethanol/gasoline blend. All of the engines meet the stringent ULEVII emissions certification and run on regular grade gas. The 4.0L engine is paired with a 5-speed automatic transmission, but the 4.6L and 5.7L both drive 6-speed automatics. All Tundras have a rear suspension design that maintains a level ride height even with a full load; underneath are fully boxed frame rails in front and rolled C-channel members in back. When properly equipped, the Tundra is rated to tow nearly 11,000 pounds. The Tundra has more standard safety features than most of its competitors. Front-seat side airbags are standard on all models, along with roll-sensing side-curtain airbags and a front seat knee airbags. 4-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 jackknifing. 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. While the safety features are standard across the line, the Tundra ranges from basic to very luxurious inside depending on the trim level, starting at the very frugal base model and going all the way up to the very well-appointed Limited. Different Tundra models are available, including a "Work Truck" no-frills trim level that's available in standard cab or double cab versions. It features plain black bumpers, vinyl seats, rubber floor mat and manual-adjustable mirrors. Limited Double Cab and CrewMax get equipment upgrades such as power front seats, 6-disc CD changer, heated mirrors and mud guards. The Limited model includes all the interior luxury features offered in full-size SUVs, such as dual-zone climate control, heated power front seats and a 440-watt JBL surround-sound system. At the top of the lineup is the Platinum model. Platinum Tundra's include a memory enabled power driver's seat, embroidered headrests, heated and cooled front seats, leather interior, a navigation system a wood grain interior and power moonroof. 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. A TRD (Toyota Racing Development) Off-Road Package is optional on the Tundra, bringing an off-road suspension, off-road tires, skid plates, fog lamps and more. TRD Sport and TRD Rock Warrior packages include special color-keyed bumpers. The rock Warrior also gets a special TRD-tuned off-road suspension and a backup camera, while both offer unique wheels. Other notable options include a DVD-based navigation with rearview camera, rear-seat DVD entertainment system and larger 20-inch wheels.