The 2015 Jeep Grand Cherokee is available in five trims: the base Laredo, Laredo E, Limited, Overland, Summit and the high-performance SRT. All but the SRT feature a standard 3.6L Pentastar V6 engine that makes 290 horsepower and 260 ft-lb of torque. The flexible-fuel engine features variable-valve timing and is mated to an 8-speed automatic transmission. Limited, Overland and Summit models offer a new optional 3.0L EcoDiesel V6 with 240 hp and 420 ft-lb of torque. The engine achieves up to 30 mpg on the highway and gives Grand Cherokees so equipped an effective range of up to 730 miles on a single tank of fuel. A 360-hp 5.7L Hemi V8 engine is also available on all trims but Laredo. Meanwhile the SRT comes with a 6.4L V8 that makes 465 horsepower. All but the SRT are available with either 4x2 or 4x4, while the SRT utilizes Quadratrac on-demand all-wheel drive. Independent front and multi-link rear suspension systems and a unit-body structure have made the Grand Cherokee's frame very rigid. Jeep's Quadra-Lift air suspension, capable of lifting the vehicle 4.5 inches for more off-road ground clearance and Selec-Terrain traction control systems are available on 4-wheel drive trims only. Standard safety equipment across the lineup includes 4-wheel antilock disc brakes, active head restraints, a full array of airbags, including full-length side-curtain and seat-mounted side thorax air bags, electronic stability control, electronic roll mitigation, hill-start assist, auto-on headlights, trailer-sway control and tire pressure monitoring system. Adaptive cruise control is now available, along with front collision alert and front park assist. Standard equipment on the base Laredo includes keyless entry, 17-inch aluminum wheels, dual-zone air-conditioning, a leather-wrapped steering wheel with audio controls, an anti-theft system, MP3 player and an auxiliary power outlet. Laredo E includes power adjustable front seating, SiriusXM satellite radio and roof rails. The Limited trim adds upgraded 18-inch aluminum wheels, a leather interior with power-adjustable heated seats and memory. The panoramic sunroof is an upgrade, as is a premium sound system with hard disk storage and satellite radio. Safety and convenience are enhanced with a rear parking aid, integrated turn signal mirrors, rain-sensing wipers and HID headlights. Comfort enhancements include automatic climate control, proximity entry and heated rear seats. The Overland gets 20-inch aluminum wheels, Napa leather upholstery with heated and ventilated front seats and a heated wood/leather steering wheel. It also gains a remote trunk release and a power liftgate. The Summit includes adaptive cruise control, a blind spot/rear cross-path detection system, front collision warning and exterior trim enhancements. Options available across the lineup include a rear DVD entertainment system, a full-size spare, an array of aluminum wheel options and two different levels of towing equipment. A collision preventing blind-spot/rear cross-path detection system is available, as is an adaptive cruise control with Forward Collision Warning. The 4-wheel drive models are all seriously capable, but can be outfitted to a greater degree depending on the customer's interest. Off-Road packages that include skid plates, hill descent control and a high-performance Quadra-Drive II 4-wheel drive system are available. The Grand Cherokee SRT is a different beast. Intended for on-road performance, it utilizes an on-demand 4-wheel drive system, a 465-horsepower 6.4L V8 engine and an 8-speed automatic transmission. Underneath, there's an electronic limited-slip differential, active damping suspension and performance-tuned steering. Big 20-inch aluminum wheels, special body-color trim, HID headlamps, fog lamps and rain-sensing wipers are standard as well. Inside, the SRT comes with heated and ventilated power-adjustable leather seats, a heated steering wheel and keyless proximity entry.