November 13^th, 2005

The New GMT900s (from the perspective of GMT800)

2007 Chevrolet Tahoe/ GMC Yukon/ Cadillac Escalade - the most improved vehicles of the year?

Shown in depth at Friday's Florida Auto Show press preview in Miami, the 2007 Cadillac Escalade caps the range of new GMT900 full-size SUVs. Escalade will be available in seven exterior colors. Heated and cooled seats, and heated steering-wheel, are optional, as are the rear-seat DVD; DVD navigation; rearview camera; IntelliB-eam headlamps, and a sunroof. As before, Escalade is derived from the Tahoe/ Yukon (below), which thems-elves are sourced from pickup trucks. These new GMT900 half-ton pickups - Silverado and Sierra - are expected at the 2006 North American International Auto Show in Detroit, in January. Escalade ESV which has been a derivative of the longer (by 22-inches, 90% of which goes toward interior space) Chevrolet Suburban and GMC Yukon XL, will be launched later next year. Escalade EXT, too, will follow later, upon January's launch of the next-generation GMT900 Chevrolet Aval-anche

2007 Chevrolet Tahoe

2007 GMC Yukon Denali

After the Tahoe's September preview, GMC in October showed the Yukon and Yukon Denali in its largest market: California, where the division's sales have increased 28% over the past three years, and 25% last year. The upscale Denali has a bolder, signature chrome grille, and unique headlamps and tail-lamps. Featuring four engines between them, each the fourth-generation of the Chevy small-block launched in 1955, and a redesigned frame; front suspension; rack-and-pinion steering, and interiors, Tahoe; Yukon, and Escalade go on sale early next January. Production starts in Arlington, Texas, on December 5th. The Tahoe can tow 7,200lbs in two-wheel-drive, 4.8-liter V8 form (to be joined by a 2WD Yukon later in 2006), and 7,700lbs with four-wheel-drive. The upcoming Suburban/ Yukon XL/ Escalade ESV are expected to be able to pull up to 9,800lbs

GMT800 Chevrolet Tahoe/ Suburban

GMT800 Cadillac Escalade/ ESV/ EXT

Tahoe began climbing the sales charts in 1997, 53% up for that year. Launched for 2000, the current, second-generation GMT800 Tahoe has been America's best-selling full-size SUV for the past four years; the sales leader in a body-on-frame bruiser segment that accounts for 750,000 annual units – and once managed 1 million. GMT800 near-luxury and luxury SUVs are widely held to be among the best in their classes. Per GM Vice Chairman Bob Lutz, then, it is unsurprising that - again - changes to create GMT900 have been evolutionary

GMT900 2007 Chevrolet Tahoe

The Tahoe retains the dual-level head-lights that have been a feature of full-size Chevrolets in one form or another since 1973, albeit that, here, the headlights consist of two horizontally-mounted circles, underlined by the indicators at the bottom in a flush, uninterrupted unit. The front fascia is upturned in V-form at its corners, not quite to the extent of the current Silverado pickup truck, but a marked departure from the more horizontal, softer, current Tahoe. All GMT900s boast doors which wrap over the rocker panels. Wheelarch lines have dropped as wheels have grown larger, an effort to attain a more powerful wheel-to-wheelarch relationship. The tips of the wheel-arches are softer; the angle-of-attack of the windshield less violent, yet the D-pillar is now proudly exposed, rather than hidden by black plastic as it has been for more than a decade. Chrome is used as a garnish rather than for the surface of an entire plane, and driving lights are circular rather than trapezoidal

2007 Chevrolet Tahoe

2007 Cadillac Escalade

Dashboard plastics are vastly improved, with premium materials offering much lower gloss levels. Per the newer generation of GM products, control tactility is better, too. Gaps throughout the interior are under 1mm – most, under 0.5mm in the Escalade. There are no exposed fasteners, and no exposed seat mechanics. Ergonomically, the outgoing, GMT800's consoles have been a reach for the driver, and the climate controls are obscured by the column-mounted trans-mission lever. For GMT900, instrument panels have been moved down and forward by six inches, for improved ergonomics. Instrument clusters now feature round – rather than semi-circular - dials, chrome-ringed as are most of the minor controls. The Escalade interior is offered in Ebony or Cashmere, with a unique instrument panel featuring white-LED backlighting, and Nuance leather seats; door trim, and center console. Cargo storage is up in every aspect, with the largest console storage in the segment

One might miss the look of  the Bvlgari clock in the 2002-2006 Escalade, tacked-on though it might have been. On the other hand, the new interior offers a more integrated approach to luxury

2002-2006 Cadillac Escalade

As the first three GMT900 launches have played out over these past two months, we availed ourselves of a GMT800, 2006 Cadillac Escalade to take stock of the current vehicles; to isolate aspects that needed improvement, and to speculate on how well the next-generation will perform, based on GMT900 information GM has made available. That the Escalade has meant so much to Cadillac's revitalization is, from the perspective of the traditional enthusiast, perhaps surprising; yet more remarkable still is that it almost never existed at all. For Cadillac at one time, much as for Jaguar now, a luxury SUV seemed an anathema, particularly in the context of (what would become) a $6 billion program of inherent improvement

1996 Lexus LX450

1998 Lincoln Navigator

The competition, however, had other ideas. When a company known for aerodyn-amics – Lexus – announced plans to lay wood and leather upon Toyota's comparatively agricultural Land Cruiser to create the LX450, and when Lincoln released its '98 Navigator, a variant of the Ford Expedition, Cadillac was pushed to reconsider

1999-2000 Cadillac Escalade

Escalade was the first Cadillac with factory-installed Onstar. Six years on, and now being applied across the Cadillac range and other GM divisions, the much-praised Onstar added Cadillac Virtual Advisor recently, providing three-day weather forecasts and traffic information, and reporting information on up to ten selected stocks

Equipped with the Vortec 345hp, 380lb-ft, 6.0-liter High Output V8 engine and heavy-duty 4L60-E four-speed Hydra-Matic, our test GMT800, 2006 Escalade – at $56,405 plus destination charge - is the world's most powerful 7-passenger full-size sport utility vehicle. Driven solemnly, if firmly, Escalade's Hydra-Matic proves perfectly adequate; only in downshifting does transmission lash rear the car with an unseemly lurch, although the puissant roar of from a disturbed engine room proves of some consolation

In the outgoing '06 Escalade, all-wheel-drive is of the Borg-Warner, one-speed, full-time open-differential variety. Now, the third-generation, 2007 Escalade will feature the four-wheel-drive system previously available on the 2003 Lincoln Navigator, as well as matching that vehicle's power liftgate and power deployable running boards. Of note: an air filter restriction/ life indicator under the hood. The EPA estimates the 2006 Escalade at 13/17mpg cty/hwy, with 15mpg comb-ined. The best average mileage we attained was 15.5mpg, with 14.9mpg being more realistic. The 2007 Escalade sees the old car's 345hp and raises it by 17%, to 403hp. Yet Cadillac promises up to 2mpg better on the highway

GMT800 2006 Cadillac Escalade

The dashboards of GMT800 vehicles have been driver-oriented and functional; their seats, comfortable. Yet the luxuriousness of these interiors has regularly been called into question. Much of the luxury in the Escalade feels tacked-on. Even as some of the periphery is engaging, on an individual basis, this is a Chevrolet first, a Cadillac second. GMT900 will be a more inherent experience

What the Escalade is not possessed of is a Cadillac-like ride, its heavy rear axle shuddering over bumps, and yet its long-travel springs absorbing large potholes with no fuss. Smaller undulations, however, do disturb the Escalade, adding to the engine vibrations felt through the steering column. With the help of adjustable damping, Escalade is not a vehicle that requires a vicious grabbing of the wheel but, rather, is one whose chassis sets in curves with surprising linearity; all the more shocking given the overboosted feel in the steering. It is surprisingly adept, although it takes courage to ignore the vagueness of Escalade's recirculating-ball steering, and the collective heaving of its 5,500 pounds, as sprung weight pitches and rolls, and as the battering that road deals unsprung weight adds shakes and judders. Wind noise in the Escalade is not an issue, even around the upright windshield and those massive side mirrors. That said, one is constantly aware of the engine and the drivetrain, at anything over 2,500rpm. There is a touch of transmission whine and, on kickdown, the engine drowns out all else. There is, too, quite a bit of driveline shunt under rapidly changing throttle application; this is a vehicle that demands to be driven smoothly

The 2007 Escalade weighs about 200lbs over the outgoing model, with weight distribution at a commendable 58/42. The new front suspension features a 36mm stabilizer (28mm at the rear), with a 17.75:1 steering ratio and 3 turns, lock-to-lock. Aluminum lower control arms reduce unsprung mass by 20 pounds

The outgoing Escalade exemplifies Cadillac as it once was; based on lower-end vehicles, and visibly related to them, but expansively - if not entirely convincingly, from an inherent perspec-tive - more upscale. Arlington, Texas builds these things well; the only problem we noted was, on one morning, intermittent functionality of the seat heaters. Restarting the engine fixed it, and it never reoccurred. It bears remembering that an entire Pontiac Solstice is riding over Escal-ade's front axle. The Escalade's lack of rigidity, belying its sheer suspension travel and 10.7-inches of ground clearance, is ultimately its downfall. No amount of burled walnut; Nuance leather, or bright chrome; traction control or StabiliTrak, can disguise that this is a savage beast – yet, one we warmed to. Yet respect or revile it, there is no doubt that Escalade has provided Cadillac with a new kind of buyer - one twelve years younger than the average Cadillac customer, yet with an average income of $150,000. In a reversal, Cadillac now cites Escalade's "self-assured stance and strong lines," and has strongly promoted the Art & Science sheer, chiseled shapes which, after all, feature less on Escalade than on the rest of the range. Paradoxically, Cadillac also views Escalade as a symbol of its $6 billion revitalization!

2002-2006 Cadillac Escalade

2003 Cadillac Sixteen Concept

2007 Cadillac Escalade

Another key icon in Cadillac's renaiss-ance was, of course, the 2003 Sixteen Concept, and Cadillac is keen to point out the Sixteen's grille; front fender vent ports, and chrome accents across the Escalade. At the rear, LED taillamps and high-mount stop light feature, with standard 18-inch wheels – and available 22-inchers – offering a commanding stance

Attention to detail? The Cadillac crest is embossed in the headlamp units

Regardless of what the media might have us believe, these full-size vehicles continue to be relevant in today's marketplace - and, with the changes instituted from GMT800 to GMT900, more so than ever. For pulling a boat with up to eight passengers and their cargo, additionally, in tow, these will be hard to beat. As Buick-Pontiac-GMC General Manager John Larson puts it, "we believe very strongly that the full-size utility segment offers capability and functionality that you just can't get in any other segment." Indeed. A hefty dose of outward attitude, belied by more luxury and livability within, will not hurt, either

The three new GMT900 full-size SUVs shown over the past two months, and the upcoming pickup trucks which support them, are more than simply the continuation of a natural home for GM's torquey, overhead-valve engines, or new entries in a segment where the longevity of GM's powertrains is uncharacteristically recognized.

Shared between GM's Chevrolet; GMC, and Cadillac divisions, the GMT900 products exhibited thus far are an opportunity to shine - to improve upon GMT800 near-luxury SUV and luxury SUVs which tend to be at, or near, the top of their segments.

Tahoe and Yukon compete against Ford's Expedition; Nissan's Armada, and Toyota's Sequoia and Land Cruiser, while Escalade goes up against Lincoln's Navigator; Infiniti's QX56; Land Rover's Range Rover, and Lexus' LX470. This is the full-size (and premium full-size) corner of the market, where wheelbases run from 116 through 130-inches; lengths average 200-inches, and curb weights are well over 5,000 pounds, all in the pursuit of seven-to-nine-passenger capacities, and of the ability to tow over (often, well over) 7,000 pounds.

• The pickup trucks are due at the North American International Auto Show, in January.
   

• The three short-wheelbase SUVs they support - Chevrolet's Tahoe; GMC's Yukon, and Cadillac's Escalade - have been shown, and will see production in less than a month.
   

• Longer-wheelbase versions of each - Suburban; Yukon XL, and Escalade ESV - will be launched later next year.

Tahoe; Yukon, and Escalade are the subject of this article.

The Tahoe nameplate dates back to 1995, when - as Blazer (now TrailBlazer) became associated with a new, compact sport-utility vehicle - Tahoe was applied solely to GM's full-sized SUV.

Formerly known as K-Blazer, the '95 Tahoe was initially available only as a two-door, with 200hp 5.7-liter V8 (mated to either five-speed manual or four-speed automatic) and 180hp 6.5-liter turbodiesel. Meanwhile, a four-door GMC Yukon appeared, pushing Yukon sales upward by more than 100%. So a four-door Tahoe, six-inches longer in wheelbase and ten-inches longer overall, entered the market as a '96 model. GM cited changing demographics of SUV buyers - more couples and families than singles - as reason for providing extra doors, and thus easier access to the rear seats. As a corollary, the Yukon added a two-wheel-drive model.

Tahoe began climbing the sales charts in 1997, 53% up for that year, as the standard four-speed automatic (4L60-E) was beefed-up, and the heavy-duty four-speed 4L80-E unit's computer was revised for better economy and smoother shifts. Further mainstreaming resulted in Auto-Trac electronic transfer cases in Tahoes and Suburbans for 1998, and GMC's Yukon for 1999. By 2000, when the GMT800 generation debuted, manual transfer cases were reserved only for pickups.

Then, of course, there was Cadillac's Escalade.

That the Escalade has meant so much to Cadillac's revitalization is, from the perspective of the traditional enthusiast, perhaps surprising; yet more remarkable still is that it almost never existed at all. Back when the now-outgoing GMT800 was in its development stages, in the early days of 1995, Cadillac took the decision not to sign on to the program. For Cadillac at the time, much as for Jaguar now, a luxury SUV seemed an anathema, particularly in the context of (what would become) a $6 billion program of inherent improvement.

Its identity muddled by years of mismanagement, Cadillac, saddled with a line of aging, front-wheel-drive luxobarges that confused its aging customer base, was seeking a thorough reexamination of what it had meant to buyers in decades past, looking for how best to recapture that connotation for the Millennium. When Art & Science was decided upon, visually supported by a Wayne Cherry-mandated set of sheer forms and intense detailing, an expedient body-on-frame behemoth struck the powers-that-be as the furthest possible deviation from the new strategy.

The competition, however, had other ideas. When a division known for aerodynamics – Lexus – announced plans to lay wood and leather upon Toyota's Land Cruiser to create the LX450, and when Lincoln released its '98 Navigator, a variant of the Ford Expedition, Cadillac was pushed to reconsider.

Looking around the GM stable for donor vehicles, Cadillac noted that 97% of GM's SUVs and 70% of its pickup trucks at the time had trim that the company described as uplevel, and that more than half of the GM pickups sold had leather seats.

What former GM General Manager of Corporate Strategy and Knowledge Development Vincent P. Barabba (see Recommended Reading) might call an anticipate-and-lead strategy, one exemplified by concept cars such as the Cadillac Cien and the upcoming rear-wheel-drive CTS sports sedan which shared a few of Cien's shocking cues, was temporarily set aside in the pursuit of market share and profitability.

For 1999, GMC had launched the Yukon-based Denali, with crystal halogen headlights in a distinct fascia. The Denali name derived from Denali National Park and Preserve in Alaska, home to Mt. McKinley, the highest peak in North America.

Now, with the Denali-based '99 Escalade, Cadillac had a body-on-frame variant of a Chevrolet for the first time in many years – and, perhaps counter-intuitively, a hot seller. Though a GMC Yukon Denali (down to the rear leaf springs and drum brakes) with a Cadillac crest; softer suspension, and tweaked steering (representing all the changes Cadillac could make in the seven months it had to bring Escalade to market), the new truck was in demand. At 25,000 annual copies for 1999 and 2000, Escalade sales surpassed Cadillac's expectations by 70%.

Escalade was not done yet. When the second-generation, GMT800 Escalade launched for 2002, two additional variants were offered. Cadillac figured that 20% of luxury households - and 23% of Cadillac households - owned a full-size pickup. So Escalade EXT, with its 5-foot bed (expandable to 8-feet, 1-inch), has been the upscale cousin of the Chevrolet Avalanche, with the usual Escalade interior enhancements; an optional power sliding tonneau cover, and a sliding load floor. The lack of rear weight reduces the EXT's stabilizer from 32mm to 29mm, and the assumption that it might be used for rougher work gives it a slower steering ratio, lock-to-lock (3.3 turns, rather than 3), but it is otherwise mechanically similar to the 130-inch-wheelbase Escalade ESV (the second variation on the theme).

As outdated as its interpretation of luxury might have seemed (note that there has not even been a remote-starting feature until the new GMT900), Escalade would grow to become near-eulogized in modern music. As clumsy as some of its moves could be at speed, Escalade took pride of place in the garages of sports and entertainment icons (hence the preview of the new truck, Wednesday night, on Rodeo Drive). Domestic luxury, it seemed, was as it had ever been: excess, in size; heft, and ladled-on equipment. Cadillac could not build enough to meet demand.

For many, it might be hard to see why the Escalade - a Texas-built version of a truck that was once dubbed, Like a Rock, rather than a tall wagon based on a sports sedan that made Cadillac more credible in the eyes of import-oriented buyers - has succeeded. It helps to consider, however, that some interesting parallels might be drawn between the Cadillac's background, and that of those most visibly drawn toward it. To wit, the Escalade might be said to have made it precisely because it flaunts its rough edges, its reminders of humbler, more genuine beginnings that lend it intangible street cred.

This phenomenon, incidentally, has not escaped Mercedes-Benz, whose G-Class will - the company announced this past week - not be discontinued in favor of the new GL-Class. The square, military-vehicle-derived G-Class hardly represents the ultimate in innovation from Sindelfingen, yet - like the Escalade - it has enjoyed appreciation in the social stratosphere.

Put more simply, Cadillac garnered favor by doing the unexpected, if in a rather obvious way, thus rediscovering its swagger. We confess that the contradictions would boggle the mind of the best marketer.

Yet Cadillac, certainly, has a grasp of the brief. The brand has garnered over 36% of the luxury full-size sport-utility segment. Moreover, respect or revile it, there is no doubt that Escalade has provided Cadillac with a new kind of buyer - one twelve years younger than the average Cadillac customer, yet with an average income of $150,000.

As the first three GMT900 launches have played out over these past two months, we availed ourselves of a garden-variety GMT800, crew-cab '06 Silverado, and of a top-line GMT800, the '06 Escalade, to take stock of the current vehicles; to isolate aspects that needed improvement, and to speculate on how well the next-generation will perform, based on GMT900 information GM has made available.

Launched as '00 models based on a '99 line of pickup trucks, the current, outgoing GMT800 series of near-luxury and luxury full-size SUVs are widely held to be among the best of their kind. At their introduction, they were clearly conservative in their changes so as not to disrupt loyal customers in this most brand-loyal segment of the market. 4.8-liter; 5.3-liter, and 6.0-liter Vortec V8 engines featured as new, and more efficient, with standard ABS and standard four-wheel-disc brakes on four-wheel-drive models.  Turning circles were tighter despite these vehicles increased bulk (including 50-inch² heated outside mirrors), while GM sought to make them friendlier, using recycled plastic moldings; eliminating mercury in their lamp switches; making radiator air baffles from recycled tires, and hubcaps, from recycled Saturn car fenders.

Seven years on, for 2007, the new short-wheelbase GMT900's 116-inch wheelbase is identical to the equivalent GMT800s', although overall length is up by 5.1-inches, emphasizing both 17.7-inches of additional crush space at the front and more cargo space at the rear. Width and height are, more or less, par with the current generation's. Load capacity is increased by five percent.

Inside, packaging is now dramatically improved, notable in a segment where the intelligence of interior packaging has only recently begun to fit the expansive promise of these vehicles' exteriors. Front hip room is increased and legroom is segment-leading, while second-row legroom and knee room, and third-row headroom, are improved over the previous models. Shoulder room in the second row is up despite the addition of roof-mounted head-curtain side air bags while, in the third row, it is up dramatically, identical overall width between the new and current-generation vehicles notwithstanding. Cargo capacity is up in every respect, down to vast center consoles, and 25% larger glove boxes. The second row features an optional powered fold-and-tumble feature; push a button in the overhead console or in the rear-door pillars, and the seats are unlatched, and sent to their folded positions.

With all this in mind, we departed in our test 2006 Escalade, the vehicle that the new, GMT900 Escalade will soon replace. Equipped with the 345hp @ 5,200rpm, 380lb-ft @ 4,000rpm, 6.0-liter High Output Vortec V8 engine and heavy-duty 4L60-E four-speed Hydra-Matic, our car – at $56,405 plus destination charge - is the world's most powerful 7-passenger full-size sport utility vehicle. Indeed, the 5,500lb monster surges forward from rest, through its 3.06:1 first gear, with ease, going to its 5,600rpm red-line and eventually settling happily into a 0.70:1 cruise in fourth. For 2007, Escalade will retain its title, featuring a 403hp 6.2-liter V8 with VVT, and a new 6L80 Hydra-Matic six-speed automatic with manumatic; two overdrive gears, and a wide, 6.04:1 overall ratio.

This engine's variable valve timing, optimizing camshaft timing to improve low-rpm torque and high-rpm horsepower, is the industry's first application of VVT on a mass-produced, V8 overhead-valve engine, echoing GM's achievement (celebrated by Popular Science) in the six-cylinder pushrod realm with the 3.5-liter and 3.9-liter VVT earlier this year. The heads of the new 6.2-liter are touted to derive from the racing-derived cylinder heads of the Corvette Z06's LS7 7.0-liter engine, with airflow supported by large 55mm intake valves and 40.4mm exhaust valves.

The 2007 Escalade can thus afford feature a 3.42:1 final drive, for fuel economy (and a mere 1,500rpm at 60mph), versus the shorter 3.73:1 final drive with which our '06 model is equipped. Meanwhile, four choices of rear axle ratios are offered on the '07 Tahoe and Yukon: 3.23; 3.42; 3.73, and 4.10.

Some will be disappointed that the six-speed automatic is not standard across the board. Tahoe and Yukon - Denali aside - will retain the 4L60-E four-speed automatic. One imagines that General Motors plans to introduce the six-speeder gradually across the range, over the coming years. It must be said, however, that 4L60 four-speed auto 'box is reasonably smooth in its current iteration, while adroitly responding to the driver's right foot. In our test Escalade, it proves perfectly adequate; only in downshifting (particularly into second) does transmission lash rear the car with an unseemly lurch, although the puissant roar of from a disturbed engine room proves of some consolation.

What the outgoing, 2006 Escalade is not possessed of is a Cadillac-like ride, its heavy rear axle shuddering over bumps, and yet its long-travel springs absorbing large potholes with no fuss. These types of vehicles have ever been thus. Over Michigan backroad railroad tracks, Escalade refuses to bottom out.

Bounding motion is generally controlled, with discernible adjustment of damping rates, although the system can be caught out by changing surfaces. We figure that the adjustable damping is doing its job, a thought borne out in that the Escalade is not a vehicle that requires a vicious grabbing of the wheel but, rather, is one whose chassis sets in curves with surprising linearity; all the more shocking, as the steering feels rather overboosted. Smaller undulations do disturb the Escalade, adding to the engine vibrations felt through the steering column.

Underneath '06 Escalade sit torsion bars at the front, teamed with a 5-link coil spring configuration at the rear, with 32mm stabilizers across both. The latter aspect, together with a near-50/50 weight distribution and one-inch wider rear track (66-inches) than front, makes for surprising adeptness. It does, however, take courage to ignore the vagueness of Escalade's recirculating-ball steering (which, despite relatively quick 12.7:1 assistance and 3-turns lock-to-lock, never attempts to tell of the forces upon the front tires), and the collective heaving of its 5,500 pounds, as sprung weight pitches and rolls, and as the battering that road deals unsprung weight adds shakes and judders.

The security of ESV's longer (130-inch) wheelbase - and ~20mm lowered body - has enabled that car's steering assistance to be a touch more pronounced (14:1), but reduces the rear stabilizer's diameter by 2mm.

For the 2007 GMT900s, handling is promised to be tops, even as the Chevrolet Tahoe range - for instance - has gained an average of 9% in weight. The new fully-boxed frame with hydroformed front and rear sections offers 49% increased torsional rigidity, and 35% better beaming frequency. Front tracks are 3-inches wider, the better to squeeze in rack-and-pinion steering, with 1-inch wider rear tracks and a lower center of gravity. The 2007 Escalade features a 36mm front and 26mm rear stabilizer, with a 17.75:1 steering ratio and 3 turns, lock-to-lock. Calipers are 50-percent stiffer; brake rotors are larger all-around; ABS is of the next-generation, four-channel variety, and the front springs have been switched from torsion bars to coils. Aluminum lower control arms reduce unsprng mass by 20 pounds. Motor Trend has suggested that GM looked closely at an independent rear end for GMT900, but that the $1,200 cost per model proved too high (Motor Trend, November 2005).  One imagines that towing ability was also a factor, although it must be said that the lack of independent rear suspension continues to prevent the rear seats from folding flat. The rear, modified, thus remains the familiar coil-sprung five-link. StabiliTrak Electronic Stability Control, now incorporating better rollover protection in proactively braking the outside front and rear wheels to reduce lateral force, is standard across the range.

Our '06 Escalade is equipped with the 245/75 R16s, although 275/55 20-inch tires have been optionally available (not recommended, obviously, for off-road use). For 2007, despite standard 17-inch wheels – rising to an available 20-inches (with 275/55 rubber!) on Tahoe and to 22-inches on Cadillac's Escalade! – GM claims that the GMT900s will lead their segments in ride quality. Optionally, Autoride electronically-controlled damping continues to be available (on Yukon SLT, and standard on Denali and Escalade) as a semi-active, two-position damping control system which pumps or bleeds an air bladder within the shock absorbers. This works in tandem with a towing package, standard on Escalade since 2004, to enhance the ride when trailering (or otherwise loaded). RSS - Road Sensing Suspension - uses a computer controller to monitor vehicle speed; wheel-to-body position; lift/ dive, and steering position, independently adjusting the damping level of each shock absorber to provide the optimum ride.

Quiet, an integral component of ride quality, has been of key importance for the GMT900s, down to equipping the Gen IV small-block Vortec V8 engines with a quieter alternator. These engines sit atop stronger cradles, mounted to stiffer brackets and new bushings, all reducing vibrations through the chassis. That said, the outgoing GMT800s have been remarkably isolated from wind noise, given the bluff face they present. In our test '06, it is simply not an issue, even around the upright windshield and those massive side mirrors. One is, however, constantly aware of the engine and the drivetrain, at anything over 2,500rpm. There is a touch of transmission whine and, on kickdown, the engine drowns out all else.

For 2007, safety is improved, both for the occupants (rear pretensioner sensors, an exclusive in this segment, and roof-mounted head-curtain side air bags both figure), and for smaller vehicles which might crash into a GMT900. The front frame has improved crush dynamics that provide the equivalent of 17.7-inches of additional crush space in vehicles that are only 3-inches longer than their predecessors. Tire pressure monitors, introduced for 2004, were once optional even on the Escalade; they will now be standard across the GMT900 line, alerting the driver to a significant reduction in pressure in one or more tires, although it is unclear whether – as in the current Escalade – the driver will be able to cycle through individual pressures on all models. At the vehicles' rears, optional rearview cameras (on Tahoe, for the first time ever on a Chevrolet) provide 20-feet of viewing distance.

Minimum ground clearance climbs from 8.4-inches to 9-inches, despite the lower center of gravity. The need for more front crush space has (in part) dropped the Tahoe's approach angle (25º to 17º), but raised the departure angle by about 2º, to 22º. Limited-slip and lockable differentials continue to be available. Our '06 Escalade features only two or all-wheel-drive, the latter being of the Borg-Warner, one-speed, full-time open-differential variety. 38% of torque is sent to the front wheels, and 62% to the rear, in normal operation, while up to 100% of the power can be sent to either axle upon slippage. True four-wheel-drive now comes (returns?) to the Escalade for 2007, as well as being extended on Tahoe and Yukon.

The dashboards of GMT800 vehicles have been driver-oriented (albeit with the console still a stretch away), and their seats – particularly in the Escalade, with its standard power lumbar and side bolster support (optional on Chevrolet and GMC pickup trucks) – comfortable. They are, primarily, functional, down to the ergonomics of the interior lighting (exemplary, if not striking).

Yet the luxuriousness of these interiors has regularly been called into question. Much of the luxury in our test Escalade feels tacked-on. GM inserts real wood in the steering-wheel rim, and attempts to match its color in the woodgrain across the dash (doing so, it must be said, admirably), but the overall effect still looks and feels much like a gussied-up Tahoe – which, of course, it is. The Escalade's floor console has been unique, with its Bvlgari clock and leather-covered storage bin, but the presence of an auxiliary CD changer - curiously, in addition to the single-disc - serves to indicate the peripheral nature of Escalade's luxury: this is a Chevrolet first, a Cadillac second.

There are, certainly, problems with the bottom-up strategy that Escalade has followed. Cadillac's motto is Art & Science, and yet, while the mainstream 2006 Chevrolet Impala will display the names of the tracks on a CD as it plays them, the luxury Escalade cannot. It also takes the CD changer a while to start up when the Escalade is restarted and, sometimes, minutes pass before it begins playing again. Even the automatic headlights are a touch agricultural; flicking the switch from AUTO to ON causes them to extinguish briefly. There is no Driver Information Center, so programming the automatic door locks is an exercise in futility: pull the turn-signal lever toward you, turn the key to RUN and back to LOCK twice, and press the door lock switch several times over to change the mode.

Mind you, some of the periphery is quite wonderful. The chrome inside door-handles are entertaining to look at, and to use, pulling upward and out. The little spotlight-like interior lamps are intriguing. Escalade's Bose stereo is brilliant, although it must be said that, with MP3-format recordings, it does overemphasize the high frequencies a touch. Power adjustable pedals; power-folding and heated mirrors, and power lumbar and side bolsters are offered in all Escalades, with separate heat for both seat bottom and seatbacks (optional on lesser GMT800s), and heat for the second row. For the ultimate experience, upgrade to the larger ESV, and select Platinum Edition, with an ebony and shale dash; shale leather seating surfaces, and pleated door panel bolsters, adding to heated and cooled cupholders.

Nonetheless, 2007 - and GMT900 - is an entirely different experience.

The first manufacturer to provide a truly upscale interior in this segment – with or without up-level appliqués – was Ford with its F-150 (our Pickup Truck of the Bear, 2005). Now, it is GM's Bob Lutz who invites the media to focus on the details: the materials, and the panel gaps. "A few years ago we were glad you didn't, but now we want you to," Autoweek quotes Lutz as urging at the Tahoe's September media preview (‘Biggest launch ever,' Wes Raynal, Autoweek, September 20^th, 2005). Where Ford places its air vents as surrounds to the center stack, the new Tahoe cites its controls below them, in direct contradiction to the last-generation. The navigation and audio controls are within the driver's line-of-sight, but the minor controls fall somewhat below. The Tahoe's dashboard is more horizontal in its form, while the F-150 features the more vertical layout to which pickup truck drivers have become accustomed. Time will tell which route the GMT900 pickups will take.

Dashboard plastics are vastly improved, with premium materials offering much lower gloss levels. Per the newer generation of GM products, control tactility is better, too. Gaps throughout the interior are under 1mm – most, under 0.5mm in the Escalade. There are no exposed fasteners, and no exposed seat mechanics.

Ergonomically, the outgoing, GMT800's consoles have been a reach for the driver, and the climate controls are obscured by the column-mounted transmission lever. For GMT900, instrument panels have been moved down and forward by six inches, for improved ergonomics. Instrument clusters now feature round – rather than semi-circular - dials, chrome-ringed as are most of the minor controls. The Escalade interior is offered in Ebony and Cashmere, with a unique instrument panel featuring white-LED backlighting, and Nuance leather seats (Cadillac leather has become a wonderful thing to behold); door trim, and center console. Manual tri-zone climate control is standard; automatic, optional on all but the Yukon Denali and Escalade). Remote starting and larger DVD screens (already upgraded from 5.8-inches to 6.5-inches for 2005), are available. Escalade features Bose 5.1 Digital Surround. As on the 2006 Buick Lucerne and Cadillac DTS, heated windshield washer fluid and rainsense front wipers are available.

GM Vice Chairman Bob Lutz is confident that GM will hold its 60-62% share of the full-size SUV pie. "I think we may maintain our volume at other people's expense, even if the segment shrinks a little bit," he mused recently. That, mind you, is up 12% on account of the current generation's, post-2000 efforts.

Motor Trend is reporting that GMT900 has been hurried to market in part because, "once the tooling costs are paid for, they'll be cheaper to build than the current models," which implies that GM can make the same money selling fewer units (Motor Trend, November 2005).

Part of Mr. Lutz's bullishness is born out in an analysis of the segment. The current, second-generation Tahoe - minus the two-door body style and diesel engines of the first series - has been America's best-selling full-size SUV for the past four years: the sales leader in a body-on-frame bruiser segment that accounts for 750,000 annual units. The full-size SUV market may have once managed 1 million units, and may be down across the board in 2005, but GMC's aging Yukon and Yukon Denali have increased their national market share by 0.6%, to 22% through August 2005. GMC's full-size SUVs attract more import-conquest customers than Ford or Dodge; enjoy customers with a higher median income ($85,000) than any other non-luxury truck manufacturer, and Yukon XL Denali owners' average household income is the highest in the segment, at almost $160,000. GMC is the second-highest volume brand at GM.

Mr. Lutz's confidence, at a time when fuel prices are a talking point, is also understandable given a relative analysis of the segment. Chevrolet's Tahoe has always been segment-competitive (and often, the leader) in fuel efficiency, lacking only that it is not flanked in the showrooms by a perceivably pious, Prius-type vehicle.

Buick-Pontiac-GMC General Manager John Larson recently told GM's Fastlane Radio, "with gas prices close to $3 per gallon, there's obviously concern with consumers... we believe very strongly that the full-size utility segment offers capability and functionality that you just can't get in any other segment.

"We think this segment will maintain a very large part of the overall marketplace, and we've focused very systematically on fuel economy as being a key issue."

The EPA estimates the 2006 Escalade at 13/17mpg cty/hwy, with 15mpg combined. The best average mileage we attained was 15.5mpg, after 75 miles of gentle driving, mostly highway. The engine registered just 13 hours of total use, our test car being brand new, so we would expect some improvement over time. In our final, more realistic round with the Escalade, we used 11.2 gallons of fuel in 167 miles, which works out to about 14.9mpg. Now consider that the 2007, GMT900 Escalade sees the old car's 345hp and raises it by 17% to 403hp. Among '06 SUVs and crossovers, this is beaten only by the $90,200, 450hp Porsche Cayenne Turbo, a vehicle with a decidedly different mission. Yet Cadillac promises up to 2mpg better on the highway.

Meanwhile, the new, four-wheel-drive 2007 Tahoe – with 5.3-liter V8 - is slated for an unadjusted combined fuel efficiency of 20.1 mpg, compared to an unadjusted combined 18.2 mpg for the current generation. The GMT900s are the first to break through this 20mpg barrier, as defined by the EPA.

So serious was fuel economy to General Motors that, USA Today reported earlier this year, it eliminated the radio antenna mast, imbedding it within the windshield instead and saving about 0.001 mpg (‘Automakers jack up mpg PDQ,' Chris Woodyard, USA Today, September 15^th, 2005). More significantly, the Tahoe and its GMT900 sister vehicles feature faster windshields (57-degrees), with flusher panel fits and more attention paid to details. GM talks of a one-piece door ring – a D-ring - reducing liftgate-to-quarter panel and liftgate-to-taillamp tolerances. As a result, short-wheelbase Tahoe; Yukon, and Escalade models are said to manage a C_d of 0.363 – a segment best, says GM (and better than a Nissan Murano's, notes Larson), albeit that frontal area figures have not been released.

Diesels may be available within two years, and it is known that GMT900 hybrids – under the GM/ DCX/ BMW hybrid research partnership – are in the works.

Also, note Displacement On Demand technology on three motors available in the GMT900 range; electronic throttle control across the board, and electric cooling fans.

With utility being an important component of the decision to buy, it is promising for the GMT900s that an old GM strength, the sheer variety of models, will continue. Toyota and Lexus offer one, 275hp V8. Ford and Lincoln offer one, 300hp V8. Land Rover's LR3 has a 216hp V6 and 300hp V8 available. Nissan and Infiniti will sell you one, 305hp V8. Land Rover's Range Rover features either 305hp V8, or 400hp supercharged V8.

In contrast, two motors are on offer in GMT900 Tahoe and Yukon SUVs - a 290hp 4.8-liter V8 and a 320hp 5.3-liter V8 - with the Yukon Denali offering a third, 380hp 6.2-liter V8. A fourth, 403hp version of the 6.2-liter is standard in the Escalade. All four motors receive new dual close-coupled catalytic converters, replacing the old 3-way type.

Some will no doubt question the existence of the midlevel, GMC line between Chevrolet and Cadillac, citing it as another example of GM having too many brands. General Motors has been criticized in recent years – and, most recently, in post-New York Auto Show rumors about the future of Buick and Pontiac – of having too many divisions and too little differentiation. With the GMT900 family, spanning three divisions and more than three times as many models, GM is keen to show that it has heard and answered these comments. The three Cadillac; Chevrolet, and GMC models shown each have individual front fascias and headlights, with Cadillac going a step further in gaining distinct front and rear doors and more chrome and expanse of LED lighting in the rear, in addition to separate LED instrument and door panels; steering-wheels; seats, and consoles.

As for GMC, aside from the division's impressive statistics as noted earlier, consider that Chevrolet customers have generally crossed over from other Chevy models, while GMC intenders have, historically at least, been business and fleet customers. Moreover, particularly since the merger of Pontiac and GMC divisions, GMC truck dealerships are usually paired with Pontiac (and, more recently, Buick), which – in a truck-crazed market, in particular – has seen the need for a second, separate truck division.

Based on what we see here, GM has a series of hits on its hands. The GMT900 vehicles may well rank among the most improved of the year, appearing to have masterfully managed age-old automotive compromises. Horsepower and fuel economy are both up, for instance, as are (GM says) ride and handling. For certain, these interiors are both more refined, and more functional. As GM's Lutz puts it, the GMT900s "work like trucks but drive like a really nice passenger car" (‘Biggest launch ever,' Wes Raynal, Autoweek, September 20^th, 2005).

As for Cadillac's Escalade, although its application of luxury continues to be more peripheral than a revitalized Cadillac has accustomed us to, the changes that have wrought GMT900 have so improved the baseline that the next-generation Escalade should be a very impressive vehicle.

"We think we'll set a new standard for full-size utilities for 2007," muses Larson. Cautiously, the media seems to agree. "They've hit the bull's-eye from what I've seen," AMCI Marketing industry analyst Jim Sanfilippo told the Detroit News Thursday morning. "My honest assessment is the prospects are very bright for this vehicle" ('Can new Escalade remain king of bling,' The Detroit News, November 10^th, 2005).