Unlike many mid-size SUVs, the truck-based 2007 Toyota 4Runner is designed to stray far from the tarmac. It has a ladder frame and a high ground clearance, and the V8 is equipped with both high and a low ranges. Two engines are available, with the base motor being a 236-horsepower 4.0L V6. A 4.7L all-aluminum V8 is optional. It uses double overhead camshafts, four vales per cylinder, variable valve timing with intelligence (VVT-i), and electronic throttle control system with intelligence (ETCS-i) to produce 260 horsepower and 306 ft-lb of torque. Both engines are paired with Toyota's five-speed automatic transmission with "artificial intelligence." Toyota claims this technology adapts to driving habits, altering when gear shifts occur to maximize power or efficiency. Buyer's can opt for rear-wheel drive or four-wheel drive, as well as SR5, SR5 Sport Edition, and Limited trim levels. The SR5 comes with hill-start assist, skid plates on the engine and fuel tank, fog lamps, power mirrors, cruise control, power locks and windows (including the rear), automatic climate control, and a CD player with an auxiliary input jack. The SR5 Sport adds an enhanced suspension, 17-inch aluminum wheels, a hood scoop, a roof rack and side steps, heated mirrors, power front seats, and a leather-wrapped steering wheel. The Limited trim receives 18-inch alloy wheels, illuminated running boards, leather seats, a six-disc CD changer, dual zone automatic climate control, and HomeLink. Standard safety equipment on all 4Runners includes stability and traction controls, anti-lock brakes with electronic brakeforce distribution, and a tire pressure monitor. Front seat-mounted air bags and first and second row side curtain air bags are optional. Other options include a third row seating, enhanced audio, a moonroof, a tow hitch, a rear seat entertainment system, and navigation.