The Toyota 4Runner is offered in variants powered by V6 or V8 engines, and with rear- or 4-wheel drive. V6 models are powered by a 4.0L DOHC engine making 236 horsepower and 266 pound-feet of torque, while V8 models have a 4.7L "i-Force" V8 making 260 horsepower and 306 lb-ft of torque. Both engines have an intelligent variable valve timing system to improve response at low and mid revs, and both include a 5-speed automatic transmission that has an adaptable shift logic for conditions such as towing. Four-wheel-drive models have a Torsen torque-sensing limited-slip center differential with locking feature, along with a low range for steep off-road inclines. On V6 models, there's a multi-mode selector, while V8 models include a full-time system. All 4WD models get several electronic aids. Downhill assist control (DAC) helps with low-speed descents while off-roading, while hill-start assist control (HAC) helps keep the vehicle from rolling back while starting on an incline or slippery surface. Toyota's VSC electronic stability control, which helps maintain control in a slide by braking the individual wheels, is standard on the 4Runner, along with anti-lock brakes with electronic brakeforce distribution and brake assist. The 4Runner has truck-based underpinnings, with body-on-frame construction and full-length boxed-section frame rails. When properly equipped, 2WD 4Runner models can tow up to 7,300 pounds, and all 4Runners include pre-wiring for an electric trailer brake controller. The Limited 4WD model can be optioned with an auto-leveling rear suspension to help stability and ride quality when towing or hauling heavy loads. The system is added onto the so-called X-REAS Sport Enhancement Suspension, a system with cross-linked shock absorbers and a central control so as to improve handling and body motion during abrupt maneuvers. The 4Runner comes with seating for five, though there's an optional third-row seat on SR5 and Limited models that expands capacity to seven. When equipped as such, the middle row tumbles forward for easy access to the third row and in either case the second row is 60/40-split and folds forward. Three different trim levels, SR5, Sport, and Limited, are offered. The base SR5 includes dual-zone automatic climate control, cruise control, a multi-information display, remote keyless entry and power windows, locks, and mirrors. Sport models add steering-wheel audio controls, tilt/telescopic steering, leather trim, and upgraded upholstery. Top of the range Limited models also get faux-wood trim, leather seats, heated seats in front, a garage door opener, an anti-theft system, and a 360-watt JBL audio system. Each model also has its own look. The SR5 has a chrome grille and trim, fog lamps, black running board, and alloy wheels, while the Sport model also gets a hood scoop, smoked chrome grille, tubular roof rack and side steps, and larger alloys. The Limited has a color-keyed grille, black roof rack, black illuminated tubular side steps and 18-inch wheels. Two new packages are available for 2009: The Urban Runner, and the Trail Edition. Available on the Sport Edition, the Urban Runner package includes a new Bluetooth- and iPod-compatible audio system with a standard TomTom personal navigation device, front and rear seating in contrasting Alcantara fabric and dark charcoal leatherette, 18-inch alloy wheels, black side steps and roof rack, and a unique rear spoiler. The Trail Edition, based on the SR5, includes the same TomTom-equipped stereo system, an electronic locking rear differential, a Torsen limited-slip center differential, unique 5-spoke 16-inch wheels, and Bilstein shocks. Trail Edition interiors feature water-resistant seats. Major options include a power moonroof with automatic wind deflector, DVD-based navigation system and Bluetooth hands-free interface.