Four years ago, a complete redesign saw Jeep's senior SUV take a big trip uptown with major improvements in overall comfort, interior quality and styling. Adding an eight-speed automatic transmission and a fuel-saving diesel engine option last year further boosted the appeal of what had already become one of our favorite midsize SUVs. That's still true for the 2015 Jeep Grand Cherokee, which sees just minor changes to its feature content.

The Grand Cherokee's availability of diesel power gives it a sizable fuel economy advantage over nearly every one of its rivals. And you won't be sacrificing much in the way of performance either, as its tidal wave of low-end torque means you've got plenty of muscle for towing or venturing off road. The downsides are that the diesel engine is more expensive than the JGC's gasoline V8 engine (our math tells us that difference is made up at the pump in about 35,000 miles) and that the vehicle doesn't seem to ride and handle quite as well with the diesel.

Given that the current-generation Jeep Grand Cherokee is notably more comfortable and civilized in daily driving than older versions, one might naturally assume that this SUV with a long-standing reputation for off-road prowess has gone soft. Worry not, outdoor recreation and sports fans, as the 2015 Grand Cherokee still has plenty of cred. Jeep offers a few different four-wheel-drive systems to choose from, and there's even an optional off-road package that features an adjustable air suspension that allows you to change the ride height from 6.6 inches for easy entry into low-clearance garages to 11.3 inches for maximum ground clearance while tackling rough terrain. If it's towing you're interested in, the JGC has you covered with the diesel or V8 engines and an impressive towing capacity of more than 7,000 pounds.

Tally it all up and you're left with one of the best picks for a do-everything midsize SUV. The Grand Cherokee's closest competitor, the Toyota 4Runner, shares the Jeep's off-road aptitude, but it doesn't offer a V8 or diesel option, and its interior simply isn't as nice. The price tag on the JGC, however, typically exceeds that of the 4Runner or popular three-row crossover SUVs like the Ford Explorer or Hyundai Santa Fe. In that sense, the Grand Cherokee is similar to the Volkswagen Touareg, which also has a classy, well-trimmed interior and the availability of a diesel engine. The VW is tuned more for on-road performance rather than off-road pursuits, however. Yes, the 2015 Jeep Grand Cherokee will likely cost you more than other midsize SUVs you may be considering, but given its welcoming cabin and wide-ranging strengths, we're fairly certain that you won't mind paying a little more for it.

The 2015 Jeep Grand Cherokee is a five-passenger midsize SUV that comes in six trim levels: Laredo, Altitude, Limited, Overland, Summit and SRT. Each is available with rear-drive (2WD) or four-wheel drive (4WD), except the high-performance SRT model, which is 4WD only.

Standard equipment for the Laredo includes 17-inch alloy wheels, automatic headlights, cruise control, foglights, keyless ignition and entry, full power accessories, dual-zone air-conditioning, a tilt-and-telescoping leather-wrapped steering wheel, Bluetooth phone and audio connectivity and a six-speaker sound system with a 5-inch touchscreen, a CD player, a USB port and an auxiliary audio jack.

The optional 23E package adds roof rails, an eight-way power driver seat (with four-way power lumbar) and satellite radio. Springing for the available Security and Convenience Group gets you a power liftgate, remote engine start, a 115-volt household-style power outlet, heated front seats and a heated steering wheel. The Laredo with 4WD can also be had with the Off-Road Adventure I Group (skid plates, a two-speed transfer case, Selec-Terrain system, hill descent control, full-size spare tire and on/off-road tires). Individual option highlights for the Laredo include 18-inch wheels, a sunroof and an 8.4-inch touchscreen display (Uconnect) with HD radio and voice commands.

The Altitude is essentially a Laredo with the 23E and Security and Convenience Group options along with body-color grille, cladding and lower fascias, 20-inch gloss black wheels, gloss back exterior accents, chrome exhaust outlets and black suede upholstery.

The Limited trim level also includes all the features of the 23E and Security and Convenience Group options along with added chrome exterior trim, 18-inch wheels, remote start, an anti-theft system, leather seating, an eight-way power passenger seat (with four-way power lumbar), driver memory settings, heated rear seats, a cargo cover, rear USB charging ports, a rearview camera, rear parking sensors and a nine-speaker premium audio system.

Optional packages for the Limited include the aforementioned Off-Road Adventure I Group, the Off-Road Adventure II Group (similar to I but adds an air suspension system and a locking rear differential) and the Luxury Group II package (panoramic sunroof, automatic wipers, xenon headlights, automatic high-beam control, upgraded leather upholstery, ventilated front seats, and a power tilt-and-telescoping steering wheel). The 8.4-inch touchscreen is still optional on the Limited, but can be further enhanced with a navigation system.

The Overland model is like the Limited but further adds 20-inch wheels, a towing package, power-folding mirrors, automatic wipers, a wood-rimmed steering wheel, the touchscreen with the navigation system and the contents of the Luxury Group II package.

The Advanced Technology Group is available for the Limited and Overland. It includes adaptive cruise control, forward collision warning (with crash mitigation), blind spot monitoring and rear cross-path detection.

The top-of-the-line Grand Cherokee Summit gets you polished 20-inch wheels, illuminated door sills, an acoustic windshield, active noise-cancelling technology, real wood cabin trim, front parking sensors, the Advanced Technology Group and a 19-speaker Harman Kardon sound system. You can further deck out the Summit with the Platinum Series package that includes a variety of exterior trim enhancements.

The high-performance SRT model is equipped like the Summit model minus a few standard features, such as the panoramic sunroof and 19-speaker audio system. The additional unique performance features include an exclusive V8 engine, 20-inch forged wheels with performance tires, LED running lights, an adaptive suspension, performance-tuned steering, Brembo brakes, a limited-slip rear differential, leather/suede sport seats and carbon-fiber cabin accents. Optional on the SRT is the Red Vapor package, which features black chrome wheels, gloss black exterior accents and silver, black and red cabin accents.

A Blu-ray-capable rear-seat entertainment system (with twin seat-mounted displays and HDMI and RCA inputs) is optional for the Limited, Overland, Summit and SRT. The towing package that's standard on the Overland and Summit models is available as an option on the Laredo, Limited and SRT trims.

Every 2015 Jeep Grand Cherokee except for the SRT version comes standard with a 3.6-liter V6 with 290 horsepower and 260 pound-feet of torque. This is the only engine you can get on the Laredos, while the Limited, Overland and Summit models offer two additional engines: a 5.7-liter V8 (360 hp and 390 lb-ft) and a turbocharged 3.0-liter diesel V6 (240 hp and 420 lb-ft). The SRT comes exclusively with a 6.4-liter V8 that produces 475 hp and 470 lb-ft. An eight-speed automatic transmission is standard across the board.

Non-SRT Grand Cherokees offer three available 4WD systems: the single-speed, light-duty Quadra-Trac I system (for the Laredos), Quadra-Trac II with a two-speed transfer case (optional on the Laredo E, standard on Limited and Overland) and Quadra-Drive II with a rear electronic limited-slip differential (optional on Limited and Overland, standard on Summit). An adaptive air suspension (Quadra-Lift) and a driver-selectable traction control system that adjusts to different terrain are also available (optional on the 4WD Limited, standard on 4WD Overland and Summit). The Grand Cherokee SRT features a specialized all-wheel-drive system tuned more for high-performance driving than off-road use.

Equipped with the standard 3.6-liter V6, the Grand Cherokee has EPA fuel economy ratings of 19 mpg combined (17 city/24 highway) with four-wheel drive and 20 mpg combined (17/25) with rear-wheel drive (2WD). At the test track, a Grand Cherokee Overland V6 with 4WD sprinted from zero to 60 mph in a fairly quick 7.9 seconds. Maximum towing capacity for a properly equipped V6 Grand Cherokee is 6,200 pounds.

Jeep Grand Cherokees equipped with the optional 5.7-liter V8 get an estimated 16 mpg combined (14 city/20 highway) with 4WD and 17 mpg combined (14/22) with 2WD. Towing capacity for Grand Cherokees with the 5.7-liter V8 tops out at 7,400 pounds. Fuel economy is vastly improved when you select the diesel V6 engine, which is EPA-rated at 24 mpg combined (21 city/28 city) with 4WD and 25 mpg combined (22/30) with rear-wheel drive. Impressively, the towing capacity with the diesel is the same as the 5.7-liter V8. During Edmunds testing, a Jeep Grand Cherokee 4WD with the diesel engine sprinted from zero to 60 mph in 7.7 seconds.

The 2015 Grand Cherokee SRT returns an estimated 15 mpg combined (13 city/19 highway), while its towing capacity stands at 7,200 pounds.

The 2015 Jeep Grand Cherokee comes with antilock disc brakes, stability and traction control, hill ascent control, hill descent control (optional on Laredo) front side airbags, side curtain airbags and active front head restraints. The Advanced Technology Group (optional on the Limited and standard on Overland, Summit and SRT) includes forward collision warning (with crash mitigation), blind spot monitoring, rear cross-path detection and lane departure warning. Upper trims also come with a rearview camera and park assist features.

In Edmunds brake testing, a diesel 4WD Jeep Grand Cherokee stopped from 60 mph in 121 feet, a respectable distance for this class, while a 4WD Grand Cherokee with the gasoline V6 needed 133 feet, which is longer than average. Meanwhile, the last SRT model we tested stopped in 109 feet, a very short distance but about what we'd expect of a high-performance SUV fitted with summer performance tires and high-performance Brembo brakes.

In government crash tests, the 4WD Grand Cherokee earned five stars (out of a possible five) for overall crash protection, and the 2WD version earned an overall rating of four stars. Both rated five stars for total frontal crash protection and five stars for total side crash protection. The reason for the one-star difference in overall rating is the 2WD version's slightly lower rollover rating.

In testing by the Insurance Institute for Highway Safety, the Jeep Grand Cherokee received the highest possible rating of "Good" in the moderate-overlap frontal-offset, side-impact and roof-strength crash tests. It earned a second-lowest "Marginal" rating in the small-overlap frontal-offset test. The Grand Cherokee's seat/head restraint design was rated "Good" for whiplash protection in rear impacts.

Even when equipped with the base gasoline V6 engine, the 2015 Jeep Grand Cherokee is plenty powerful. It also provides a quiet, comfortable ride and commendable stability around turns. The eight-speed automatic transmission is a great ally, as it makes good use of the V6's power and shifts very smoothly to boot. All in all, most shoppers should be quite satisfied with the base-engine Grand Cherokee.

If you're looking for better fuel economy, though, the diesel-powered V6 is an interesting option to consider. Plus, the diesel's high torque output makes it ideal for big-league towing jobs and off-road use. Around town, the diesel V6 can sometimes lurch in stop-and-go traffic, and it clatters quite a bit. But once it's up to speed, it's exceptionally quiet. Perhaps the biggest downside of the diesel is the sheer weight of this heavy-duty engine; diesel Grand Cherokees weigh considerably more than other versions. This added heft over the front wheels has a negative impact on the way the Jeep steers and handles -- it simply doesn't feel as precise or balanced when going around turns. In addition, our diesel Grand Cherokee test vehicle, which was equipped with the optional Quadra-Lift air suspension, wasn't especially comfortable or smooth-riding on rough city streets (though it showed good composure over larger bumps and ruts on the highway).

If fuel economy is not of particular concern, the 2015 Jeep Grand Cherokee SRT is a tower of power that accelerates and stops at rates that will impress even the most seasoned sports car driver. It's a sleeper performance vehicle if ever there was one, though its run-flat summer tires and aggressive suspension tuning result in a fairly stiff ride on city streets and highways alike.

Off-road, the Jeep Grand Cherokee is at the top of the mountain for its class. Trail obstacles and steep hills are easily dealt with regardless of which engine you choose (although the SRT version is built primarily for paved-road driving), thanks to the advanced four-wheel-drive systems and the Jeep's generous ground clearance.

Even in the lower trim levels, the Grand Cherokee's interior boasts excellent fit and finish. The dash houses a standard configurable 7-inch screen that can be used to display a wide range of information. We're especially fond of the optional center 8.4-inch touchscreen and highly recommend it. It features an easy-to-use interface and includes a WiFi hotspot and smartphone app integration (including media apps from Pandora and iHeartRadio). It also houses the navigation system if the vehicle is so equipped. Sometimes it takes a few too many touch inputs to make climate control adjustments through the touchscreen, but apart from that minor complaint, the Grand Cherokee has one of the most user-friendly cabins in this class.

While the Grand Cherokee has no third-row seat option, there's ample room for a family of four or five, and you can order up a significant amount of luxury ambience, including ventilated front seats and a dual-screen, Blu-ray-capable rear entertainment system with an HDMI input. Backseat passengers should be pretty comfortable, as the Grand Cherokee provides considerably more rear legroom than the Toyota 4Runner. With the rear seats in place, the cargo bay measures 36.3 cubic feet. With the rear seats folded down, the Jeep has 68.3 cubic feet of cargo capacity.