New hybrid model improves fuel economy.

Introduction

Faced with rising gas prices and eco-protests, the market for full-size SUVs has seen better times. General Motors answers the call for better fuel economy with the 2008 GMC Yukon Hybrid. Equipped with the new two-mode hybrid system, the Yukon Hybrid gets an EPA-rated 21 mpg City, matching ratings with a four-cylinder Camry. 

The entire GMC Yukon lineup was completely redesigned and re-engineered last year and carries into 2008 with few changes other than the addition of the Hybrid model. The Yukon rides on the same superb platform as the Chevy Suburban and Silverado. 

Yukon offers power, space, and towing capacity. It can haul large loads of gear, it can survive repeated pounding over rugged terrain, it can pull heavy trailers, all while transporting four in luxurious comfort. 

Inside, the Yukon features a simple, elegant dash that hints at aspirations for entry-luxury status. The Yukon is available with seating configurations for five to nine passengers. Seating in the first and second rows has plenty of room, but the third row is best left for kids and has to be removed for maximum cargo space. 

Engine choices include four V8s. The popular 5.3-liter V8 engine provides plenty of power and has a system that shuts down half the cylinders under light loads to improve fuel economy. The Denali model's 6.2-liter V8 generates 380 horsepower and comes with a six-speed automatic, making it almost as fuel efficient as the 5.3-liter and one of the more powerful offerings in the class. The new Hybrid powertrain features a 6.0-liter V8 boosted by two electric motors. The Hybrid delivers 332 horsepower and fuel economy that rivals some sedans. The Yukon is rated to tow up to 8200 pounds when properly equipped, enough to tow cars, boats and horses; the Hybrid has less towing capacity. 

Ride and handling characteristics are typical of large SUVs. The Yukon leans in turns and is not agile. The ride quality, on the other hand, is impressive, even with the Denali's available 20-inch polished wheels that add a touch of high fashion trendiness. 

We found the new two-mode hybrid system worked seamlessly. The system uses two electric motors in GM's new Electrically Variable Transmission (EVT) that has four fixed gears. The EVT is mated to a 6.0-liter version of the 6.2-liter V8 that also has Active Fuel Management. Total output is 332 horsepower and 367 pound-feet of torque. One of the motors aids power at low speeds and the other lends a hand at highway speeds. With just a little throttle, the electric motor can propel the Yukon up to 30 mph. Get on it a little harder, and the gasoline engine kicks in just as smoothly as in any Toyota hybrid. Like other systems, the gasoline engine turns off at stoplights and restarts as soon as it's needed. 

The better news is Hybrid fuel economy. With 2WD, the Yukon Hybrid is rated at 21 mpg in the city and 22 on the highway. With 4WD, those numbers are 20 city/20 highway. The 2WD city number matches that of the four-cylinder Toyota Camry, though the highway number is substantially less than the Camry's 31 mpg. While the Hybrid has considerably less towing capacity at 6000 pounds with 4WD and 6200 pounds with 2WD, that's still enough for the Hybrid to be used for many towing needs. 

Lineup

The 2008 GMC Yukon lineup offers a choice of four different V8 engines. Four models are offered: SLE, SLT, Denali, and the new Hybrid. All are offered with 2WD or 4WD, except the Denali, which comes standard with all-wheel drive. The available four-wheel drive (4WD) is a full-time system that can be driven on dry pavement and has low-range gearing. The Denali's all-wheel-drive system lacks low-range gearing. 

The GMC Yukon SLE 2WD ($34,790) comes with a 295-hp 4.8-liter V8 and a four-speed automatic transmission. The SLE 4WD ($38,590) comes with a 320-hp 5.3-liter V8 with Active Fuel Management and the four-speed automatic. Also available is the 5.3-liter V8 with AFM and E85 Flex-Fuel capability. 

SLE models come standard with cloth upholstery; dual-zone manual climate control front and rear; six-way power driver's seat; leather-wrapped, tilt steering wheel with audio controls; AM/FM/CD/MP3, eight-speaker stereo with XM satellite radio; OnStar assistance with one year subscription; driver information center; power windows, cruise control, heated and foldable power mirrors; auto-dimming rearview mirror; 40/20/40 split front bench seat with manual recliners; 60/40 split folding second-row bench seat; automatic headlights; roof rails; side steps; locking rear differential; three power outlets; P265/70R17 all-season tires on bright aluminum wheels. A 3SB package for SLE ($1,965) and SLE 4WD ($975) adds the Flex-Fuel 5.3 V8 (2WD), front bucket seats, a power front passenger seat, a front center console, rear radio and climate controls, and fog lights. A Convenience Package ($765) has rear-obstacle detection, dual-zone automatic climate control, power-adjustable pedals and remote engine starting. 

SLT 2WD ($38,990) and 4WD ($41,800) come standard with the 5.3-liter V8, but the 4WD model gets the Flex-Fuel version. SLT adds leather upholstery, front bucket seats, front center console, dual-zone automatic climate control with rear controls, six-disc CD changer, rear seat audio controls and outputs, universal garage door opener, fog lights, remote engine starting, front tow hooks. A 4SB option package for SLT ($4,100) adds heated, 12-way adjustable front seats with lumbar adjustment; power adjustable pedals; memory for the driver's seat and mirrors; a third-row two-passenger split folding bench seat; power-folding exterior mirrors with integrated turn signals, driver's side auto-dimming, and reverse tilting; and a roof rack. 

Options include navigation ($2,250), rear-seat DVD entertainment ($1,295), sunroof ($995), rearview camera ($250) when the navigation system is ordered. The Sun, Entertainment and Destination package ($3790) includes a navigation system, rearview camera, rear DVD entertainment, and a sunroof. A Z71 Off-Road Suspension package for the 4WD SLT ($230) includes a heavy-duty air cleaner, skid plates, off-road suspension, 265/70R17 on/off-road tires and unique alloy wheels. The third-row seat comes in two forms: two-passenger ($360 SLE, $760 SLT) and three-passenger ($460 SLE, $860 SLT). 

Also available: power liftgate ($400), roof rack cross bars ($45), power release for the second row seat ($425), heated second-row seats ($200), P275/55R20 tires on polished alloy wheels ($1,795), universal garage door opener ($105), nine-speaker Bose sound system ($495), six-disc CD changer ($300), power retractable running boards ($1,095) and remote starter ($175). Finally, by way of cold weather, towing and off-road options, but again only on some models, buyers can order one of two lower rear axle ratios ($100), an engine block heater ($75), a heavy duty transmission oil cooler ($95), a windshield washer fluid heater ($85), off-road skid plates ($150), and Autoride suspension with variable shocks and air-assisted rear load leveling ($1,120). 

Denali ($48,250) has a 380-hp 6.2-liter V8 mated to a six-speed automatic transmission with a manual shift feature. It comes fully loaded, with a wood and leather-. 

Walkaround

The GMC Yukon and Yukon Denali feature clean lines with quiet, calm surface planes that minimize the look of extended length. Likewise, the smooth, gently contoured flanks and arrow-straight beltline visually lower the height. Remarkably tight tolerances between body panels invite comparisons with the highest quality imports. 

The one-piece front end presents a friendly, welcoming face but without forfeiting the Yukon's presence. Large headlight housings promise good vision. The trademark grille and lower air intake ensure good breathing. A sharply raked windshield eases movement through the air. 

Tall, symmetrical side glass fits flush with surrounding body panels. Door handles bridging deep recesses make for easy gripping in all seasons. Squared-off wheelwells carry forward a Yukon signature styling cue. They suggest trimming up with the available 20-inch wheels and tires, though that's not our choice from a driving and towing perspective. 

At the rear, a broad, mostly flat, almost vertical tailgate resides between tall, narrow taillights. The independently hinged rear window is a nice touch, permitting easy loading of grocery bags and such. 

The Yukon lineup was completely redesigned for 2007, and the Hybrid model was added for 2008. 

The 2008 Yukon Hybrid has several styling cues that distinguish it from the other models. To reduce weight and drag, the front end features an aluminum hood, a lowered air dam, and a slightly larger grille opening. Openings that would house fog lights and tow hooks are blocked off. Along the sides, the running boards are reshaped for improved aerodynamics and the wheel flares are slightly reshaped. At the back, the rear pillars and center high-mounted stoplight have a unique shape, the tailgate is made of aluminum and has fixed glass, and LED taillights replace the standard bulbs. The wheels are more aero efficient and the tires have a lower rolling resistance. The spare tire and jack have been replaced by a tire inflation kit. The result is a 0.34 coefficient of drag and lighter weight. All of these measures add up and help improve fuel economy, if only by small amounts. 

Interior

The Yukon interior design is clean and uncluttered. Elegantly simple, the instrument panel and center stack would look right at home in a luxury SUV. The Denali is richer still, with a wood and leather-wrapped steering wheel and darker wood trim than the other models. 

We think the Yukon dashboard is a friendlier, slicker and more integrated assemblage of gauges, display screens, touch pads and control panels than those in either the Range Rover or the Mercedes-Benz GL450, both priced substantially higher than any Yukon, including the Denali. The GMC's gauge cluster is more informative, reporting via secondary analog gauges powertrain data others leave to warning lights or bury in scrollable information displays. 

Leather surfaces feel expensive, if not luxurious. The fit between panels and coverings is impressive, with tight tolerances. Less impressive is the finish of some of the hard plastic surfaces, which look better than they feel. The headliner is a woven fabric that looks and feels like mouse fur. 

The new-for-2008 Hybrid model has a unique gauge cluster with a special tachometer and an economy gauge. In the economy gauge is a green bar that represents a zone drivers can aim for to maximize fuel economy. The tachometer has an Auto Stop reading to indicate when the gasoline engine is shut off. 

The Hybrid comes standard with a navigation system and a 6.5-inch screen that shows a graphic representation of the hybrid system's power flow. This screen shows if the power is coming from the electric motors, the gasoline engine, or both, plus when regenerative braking is charging the batteries. The system also shows if the vehicle is in two- or four-wheel-drive mode. It's fun to monitor these readouts; they help you learn about how the hybrid system works and show when it is being used for the best fuel economy. But care must be taken by the driver to not be distracted by them. 

The design of the Yukon's dash gives the driver an expansive view out the windshield, adding to the feeling of being above it all. Visibility is good all around, though the imposing right side C-pillar (the post between the rear side door and the rear quarter panel) does nothing to reduce the large side mirrors' blind spot. Along the same lines, the third-row seat blocks the lower third of the rear window; folding the third row down eliminates this. 

The front seats are refreshingly comfortable and easy to adjust. They offer good thigh support, which is sometimes lacking in GM vehicles. The available second-row captain's chairs offer good thigh support, as well. We're disappointed with the folding armrests, however; they have one setting, which won't fit every occupant. Some way to adjust the angle of these armrests would be welcome. The Hybrid model has thinner front seats that reduce weight and open up slightly more second-row knee room. We found them to be as comfortable as the standard seats. 

Room for people is respectable and competitive with other full-size SUVs. In the front seat, the 2008 GMC Yukon bests the Ford Expedition, Nissan Armada, and Toyota Sequoia by several inches in all three dimensions, though all three have plenty of room. Bring your Stetson or Resistol. 

In the second row, the Yukon trails the Expedition and Armada in headroom and legroom and betters them in hiproom, but by less than an inch in all regards; it also slightly trails the Sequoia in second-row headroom, but has slightly more hiproom and considerably more legroom. In other words, all large SUVs have a lot of second-row space and the Yukon is no exception. As for second-row access, the Yukon suffers from small-feet syndrome, where the clearance between the base of the second row seat and the doorframe is so cramped, it's impossible to step in or out without turning your foot sideways. 

Third-row legroom is limited in the Yukon where we found little space for our feet and our knees wound up at chest level. The Expe. 

Driving Impression

When it comes to trucks, numbers matter, arguably more than they do with cars. The most popular engine for the GMC Yukon is the 5.3-liter V8, which produces 320 horsepower and 340 pound-feet of torque. Our test Yukon was listed at 5677 pounds. 

Examining these numbers should give a good idea of how a 5.3-liter Yukon will perform against the competition. By comparison, the 2008 Ford Expedition puts up a 5.4-liter V8 making 300 hp and 365 lb.-ft. of torque with a six-speed automatic and tips the scales at 5805 pounds. The 2008 Nissan Armada's 5.6-liter V8 makes 317 hp and 385 lb.-ft. of torque, mates to a five-speed automatic and carries a curb weight of 5593 pounds. Toyota's redesigned 2008 Sequoia is offered with a 5.7-liter V8 making 381 hp and 401 lb.-ft. of torque with a six-speed automatic and weighs 5730 pounds. 

Note, however, that the Yukon's 5.3-liter engine comes with a four-speed automatic transmission, while many full-size SUVs now come with five-, six-, and seven-speed automatics. More gears generally means smoother operation, better fuel economy, quicker acceleration performance or all three. The Yukon's four-speed automatic negates any power advantage the Yukon might otherwise have enjoyed at least as far as outright acceleration is concerned. Put another way, while it'll easily hold its own on the interstates, the Yukon isn't going to win many stoplight races. 

Not so, though, the Yukon Denali, which would leave its lesser sibling and most of the others in the dust were its driver so inclined. The Denali packs a 380-hp 6.2-liter V8 and six-speed automatic. It delivers willing power at any speed and makes the Denali feel like a much lighter vehicle. 

Fuel economy is a much better story for the Yukon. EPA fuel economy numbers range from 14 mpg city and 19 highway for the 4.8 2WD and 5.3 4WD models to 14/20 for the 5.3 2WD to 12/18 for the AWD Denali with the 6.2 V8. The Yukon's Active Fuel Management system, which shuts down half of the engine's cylinders under light load helps the 2008 Yukon best the Expedition and Armada and run neck and neck with the new Sequoia. 

In towing, the Yukon's 8200-pound rating trails all the competitors. Ford and Nissan rate their entries at a maximum of 9100 pounds, and the new Sequoia can tow up to 10,000 pounds. On the other hand, GM tends to be more conservative than other manufacturers with its tow ratings. Tow ratings have almost as much to do with lawyers and marketing professionals as they have to do with engineers. 

Driving a Yukon is pleasant. Power comes on smoothly, with no surges or hiccups, and it is accompanied by a pleasant tone that reminds us of classic dual exhaust. Transitions effected by the fuel-management system are invisible, with the only indication a telltale in the information display in the tachometer. The four-speed automatic selects gears with little fanfare. The six-speed automatic in the Yukon Denali is even smoother; it also has a manual shift function managed by a rocker switch in the handgrip on the column shift lever. 

We found the new two-mode hybrid system worked seamlessly. The system uses two electric motors in GM's new Electrically Variable Transmission (EVT) that has four fixed gears. The EVT is mated to a 6.0-liter version of the 6.2-liter V8 that also has Active Fuel Management. Total output is 332 horsepower and 367 pound-feet of torque. One of the motors aids power at low speeds and the other lends a hand at highway speeds. With just a little throttle, the electric motor can propel the Yukon up to 30 mph. Get on it a little harder, and the gasoline engine kicks in just as smoothly as in any Toyota hybrid. Like other systems, the gasoline engine turns off at stoplights and restarts as soon as it's needed. 

The better news is Hybrid fuel economy. With 2WD, the Yukon Hybrid is rated at 21 mpg in the city and 22 on the highway. With 4WD, those numbers are 20 city/20 highway. The 2WD. 

Summary

The GMC Yukon has an astonishingly fresh and comfortable interior. It offers available power that meets or beats the competition, though it trails in towing capacity. The addition of the Hybrid model answers the fuel economy issue that has long plagued large SUVs. With all its strengths, the Yukon is a strong contender in its class. 

NewCarTestDrive.com correspondent Tom Lankard drove Yukon models around Greensboro, Georgia, and Carmel Valley, California. Correspondent Kirk Bell contributed to this report from Chicago and tested the Hybrid. 

Model Lineup

GMC Yukon SLE 2WD ($34,790); Yukon SLE 4WD ($38,590); Yukon SLT 2WD ($38,990); Yukon SLT 4WD ($41,800); Yukon Denali ($48,250) Yukon Hybrid 2WD; Yukon Hybrid 4WD. 

Assembled In

Arlington, Texas; Janesville, Wisconsin. 

Options As Tested

Convenience Package ($765) with rear-obstacle detection, dual-zone automatic climate control, power-adjustable pedals and remote engine starting; three-passenger third-row seat ($460); in-dash 6-disc CD changer ($300); roof rail cross bars ($45); off-road skid plates ($150).