Sometimes you just need something big, something strong, something with genuine four-wheel drive and you need it all in one truck.A truck that will tow a sizable trailer and carry lots of people or haul a load of cargo over primitive roads is an indispensible tool for those who need it.That's the Suburban's mission.It has gotten more luxurious over the years, sometimes becoming a substitute for a large sedan.

For 2009, the Suburban comes with a new six-speed automatic transmission.An integrated trailer brake controller is now available, which is a great feature for towing.Also new is the latest OnStar version 8.0, Bluetooth, wheels, colors, an added third screen for the rear-seat entertainment option, XM NavTraffic, two choices of backup camera systems, side Blind Zone Alert option, more standards on LTZ (such as heated and cooled memory front seats), a Luxury package to bring a 2LT trim-level closer to LTZ spec.The Suburban was completely redesigned for 2007.

Suburban can handle 137 cubic feet of cargo, or up to nine passengers and 45 cubic feet or stuff, and myriad combinations in between.Two weight classes are offered, the normal 1500 and the heavy-duty 2500.

The Suburban competes with the Ford Expedition EL (8 seats max), the GMC Yukon XL, the Cadillac Escalade ESV (more features and power, no low-range 4WD), Lincoln Navigator L, Toyota Sequoia and Nissan Armada.

Every 1500 comes standard with one of three 310-hp 5.3-liter V8 engines, each with AFM which switches off half of the cylinders when the power or idle smoothness isn't needed.The 1500 2WD LS gets an iron-block engine and the E85-capable version is available on LS (no charge) and standard on LT-and-up.All 1500 4WD trucks come with an aluminum-block, E85-capable 5.3 standard.EPA ratings for 5.3-powered Suburbans run 14 city/19-20 highway on gasoline and 10/15 mpg on E85.

An aluminum-block, 366-hp 6-liter V8 with AFM and variable valve timing is optional on all 1500 (around $1100).EPA ratings for 2WD are 14/19 mpg; expect 4WD numbers to be equal or 1 mpg lower.

2500 series Suburbans come only with a heavy-duty iron-block, 352-hp 6-liter V8 and stronger six-speed automatic transmission.Although there are no badges or names denoting 2500 these heavy-duty Suburbans use different steering gear, brake parts, suspension, alternators, wheels, tires, axles and fuel tank than 1500-series.All prices given below are for 1500-series trucks and are Manufacturer's Suggested Retail Prices that do not include the destination charge.Approximate $1400-$2000 more for a 2500 series, which range from $41,980-$45,495 in 2WD and $44,820-$48,340 for 4WD.

Standard equipment on the 1500 LS 2WD ($40,370) and 1500 LS 4WD ($43,215) includes cloth interior, power locks and windows, air conditioning, leather wheel with cruise and audio controls, tinted rear windows; roof rails (crossbars are extra), folding power heated mirrors, recovery hooks, a seven-wire trailer harness, 17-inch aluminum wheels, three power outlets, AM/FM/XM/CD/MP3 sound system with eight speakers (3 month XM trial), center fold-down armrest with storage, overhead console, cruise control, 40/20/40 split front bench seat with six-way power adjustment for the driver, 60/40 second-row seat, 50/50 third-row split-bench seat, and OnStar 8.0 with one-year Safe & Sound service plan.4WD versions add the aluminum-block flex-fuel V8 and Autotrac 4WD system that has on-pavement all-wheel drive ability.

LS-grade options include a Convenience package (adjustable pedals, remote start, rear park assist, and rear camera display in rear-view mirror ($1060), trailer package ($230), locking differential ($295), integrated trailer brake controller ($200), 3.42:1 axle ratio (no charge), floor mats, flex-fuel E85 engine (no charge), and engine block heater ($75).

The LT 2WD ($41,380) and 4WD ($44,225) come with front bucket power seats and a floor console between them, flex-fuel engine, 60/40 split-recline second row, cargo shade, fog lamps and paint-matched mirrors, door handles and side moldings.OnStar is upgraded to Directions & Connections service, which includes Turn-by-Turn Navigation.

Options on 1LT trucks include the Convenience and Trailering packages, 6-liter V8, rear entertainment system ($1295), third-row screen ($600), navigation with XM NavTraffic ($2500 plus XM subscription), 20-inch wheels ($1795), three-zone air conditioning ($195), and UGDO ($120).

The 2LT 2WD ($43,905) and 4WD ($46,750) models add leather upholstery for first and second-row seats, three-zone AC, adjustable pedals, rear audio controls, CD changer, and rear park assist.Options include the 6-liter V8, Autoride suspension with rear air assist/self-leveling, rear entertainment, navigation, skid plates, Bose audio system upgrade ($500) and a Luxury package (heated 10-way front and power-release second-row buckets, Bose audio, power-folding mirrors, power liftgate, auto-dimming mirrors with turn signals).

A Z71 off-road package is offered only on LT trucks, in 2WD or 4WD.It adds a different chrome grille and fascia, rectangular fog lamps, body-colored fender flares, mirrors and door handles, tubular assist steps, 18-inch wheels with on/off road tires, off-road suspension package, automatic locking differential, skid plate, higher-capacity air cleaner.and badges.

At the top of the half-ton line is the LTZ ($50,615) and LTZ 4WD ($53,460), which includes the contents of the 2LT Luxury package, heated and cooled perforated leather front seats with memory, Bose Centerpoint surround sound system, Autoride, locking differential, remote start, chrome mirrors, 20-inch aluminum wheels, and rain-sensing wipers.Options include navigation, rear entertainment, floor mats ($276 for entire truck) and side Blind Zone Alert ($500).

Safety equipment on all models includes dual frontal airbags, full-length head-curtain airbags, front seat belt pretensioners, a tire-pressure monitor, anti-lock disc brakes with electronic proportioning, and StabiliTrak, GM's electronic stability program with anti-rollover mitigation and traction control.OnStar telematics will send help if the airbags deploy and you don't respond.Safety-related options include rear park assist, rear-view camera, and side Blind Zone Alert.Side airbags are not available.

The profile is elegant in its simplicity, no lines drawing the eye up or down, just a smooth clean surface from one end to the other like an aircraft.Big boxes are best carried in big boxes, not sloping hatchbacks.

The 'Burb has a square-jawed face that's smooth and rugged at the same time, a twin to the shorter Tahoe.The mesh grille is split by a gold Chevy bowtie, and the daytime running lights use separate lamps and can be switched off for after-dark campground arrivals.The bumper fascia reveals a low license-plate holder sandwiched by openings for tow hooks, with small round fog lamps at the corners like single teardrops falling from the headlamp eyes.The seam between the fascia and fenders is very tight, and a good indication of GM's solid body quality on the current generation of trucks.

Rake was added to the windshield for 2007, improving aerodynamics and looks.The hood has two long bulges at its sides, reaching almost from windshield to grille; Chevy calls these twin bulges the power dome; we call them a good way to keep such a large expanse of otherwise-flat steel from fluttering, just as long-cab pickups have grooves on the roof.For aesthetics we would prefer if the roof-mounted antenna were centered but long, flat cargo on the roof might present a problem.

The rear liftgate is vertical, and the rear window opens independently, with both the manual and power liftgate, which is aluminum, reducing the weight and thus the effort to raise and lower it.Rear wiper coverage is average at best.The barn-door side-swinging rear doors of the predecessor are no longer offered.

Although the lines remain the same, the Suburban's ultimate appeal depends on which trim level and wheel style and size you choose.Some are nearly void of chrome while the Z71 adds machismo with sizable fender flares and side steps so short drivers can get in and tall ones can mess up their pant legs.

The standard wheels are five-spoke, 17-inch aluminum.Polished wheels are available.Also available are 20-inch dubs that look good, but we think they are too big for grown-ups.Taller sidewalls yield a better ride and in most consumer-magazine testing those large-diameter wheels don't go, stop or handle any better, they just ride harder so we prefer the 17-inch wheels.The Z71 package comes with 18-inch wheels.

Cargo space is plentiful, with 137.4 cubic feet of storage behind the front seats (second row folded, third row removed); if you aren't interested in cargo space you don't need a Suburban.With all the seats in place, set up for passengers, 45.8 cubic feet of cargo space is available, with 90 behind the second row, third row removed.You'll need to lift stuff about two-and-a-half feet off the ground to load the cargo area, and rear side doors without wheel cutouts make entry and loading much easier.

Given the lift-over height at the rear bumper, it's not easy to climb up in through the back to reach things, especially since there are no grab handles; nor are there standard hooks or nets in the back.But there is a nice compartment over the left wheel well, for tools, flashlights, snow chains or the like.

Smart storage space abounds.The huge console has deep storage and a tray on top.The glovebox is 25 percent larger than on pre-2007 models.There are two cup holders in a removable tray forward of the console, and one in each wide door pocket.There's a slot in the dash just left of the turn signal, perfect for coins or tickets.

Suburban offers a choice of two or three seats in the first two rows.With a middle-row bench seat the right third of the seat folds independently of the left, easing curb-side entry to the third row or allowing skis or boards on the right with two passengers on the left.With bucket seats in the second row you can climb back from either side, and those middle buckets can be released at the touch of a button or heated if you option right.Only full-size utilities and crossovers, minivans, and Ford's Flex offer the kind of room you find in these first two rows.

In the third row things get interesting.The seat has three belts but just two headrests, and it splits 50/50 right down the middle where a center passenger would go.If you want to slide a long item inside the third-row gets cut to one person; an offset split would allow long items and four passengers in back.These third-row seats do not fold flat with the floor, so if you want a long flat load deck to camp, carry building materials or hound crates, you have to haul the third-row seats out and leave them home.

Third-seat room is good compared to most three-row SUV and crossover vehicles which aren't as long, as wide or both.In full-size utes the Toyota Sequoia third row measures a fraction of an inch superior in head and legroom and an inch larger in shoulder room, but it's almost 15 inches shorter outside so cargo space behind all the occupants is half the Sub's at 20 cubic feet.However, Ford's Expedition EL, which has independent rear suspension like the Sequoia, is an inch shorter than a Suburban but offers 42.6 cubic feet of space behind the third row, one-eighth-inch less headroom, and almost three inches more leg and shoulder room, and the floor shape is more comfortable.If we're being relegated to back of the bus we prefer the Expedition EL.

Cabin materials and style show the greatest gains from earlier Suburbans with pleasant feel and appearance more car-like than utility appliance; with woodgrain trim and leather in the upper models the only reason to upgrade to an Escalade ESV would be more power but you'd lose 4WD trail ability in the process.

Analog instruments are more responsive than in any other (non-GM) big SUV, clearly labeled and nicely lit, as easily read at night as in daylight; gauges include a voltmeter, oil pressure and transmission fluid temperature.Steering wheel buttons handle audio and cruise chores, plus the message display panel on most models and the interface is fairly intuitive.Upper trims have adjustable pedals and the steering wheel tilts but it is offset and angled slightly to the right of the driver seat centerline.

The navigation system and audio system is easy to operate.It includes a touch-screen monitor.We set the programs we liked, and could switch from an XM to AM to FM to digital file with one finger push.OnStar has been further refined for 2009, XM real-time traffic data is available, and if you choose a rear camera without navigation the image is displayed in the inside mirror.

The driving position offers a good view over the low dash, perhaps the best visibility in truck-dom.Seats are designed for American comfort rather than European firmness, and can be ordered with heat and cooling on some models.

The advantages of 50 percent more gears can be seen reviewing testing done with earlier Suburbans with the 6-liter engine and 4-speed automatic competing against an Expedition EL with the it's 5.4-liter V8 and six-speed automatic.Despite the Expedition's greater weight and smaller engine it nearly matched the Suburban's empty acceleration but towed faster and got significantly better mileage towing or empty.

Since the Suburban had more horsepower, more torque, and a shorter axle ratio (improves acceleration, detracts slightly from highway economy) the six-speed automatic made the difference.With low gears that make it easier to get going, high gears that keep engine speed to a minimum on the highway, and more gears in the middle so you can tow uphill without screaming along in second gear, gains clearly exceed any added cost.

The Suburban 1500 engines rate 310 hp at 5200 rpm and 335 lb-ft of torque at 4200 rpm.By comparison the lighter Nissan Armada's 5.6-liter makes 317 hp and 385 lb-ft at lower rpm, Ford's Expedition 5.4-liter does 310 hp at 5000 rpm and 365 lb-ft at 3600 again at lower rpm.

All 1500 engines have a fuel shut-off feature that cuts fuel to half the cylinders.This will be most noticed on level ground at moderate, steady speeds.Since the axle ratios are now taller the Suburban should give better performance with no loss in fuel economy, though we haven't had a chance to run a 2009 against the others.

An optional 6-liter V8 with variable valve timing on Suburban 1500 makes 366 hp and 376 lb-ft at even higher rpm than the standard 5.3, giving it the advantage over everything except GM's 402-hp Cadillac Escalade and Toyota's quick 381-hp Sequoia.Armada and Expedition have a higher tow rating than Suburban 1500, and the Sequoia has a higher tow rating than the Suburban 2500.

On the heavy-duty Suburban an iron-block 6-liter is used, with less horsepower but more torque than the 1500, and the transmission is a stouter six-speed automatic.Like the others it features a tow/haul mode for less shift busyness over rolling terrain and adds a bit of compression braking.

The shifter has PRNDML positions and a thumb-operated rocker switch for changing gears manually.However, unlike every other +/- shifter, you first have to move the entire lever to the M position.

All Suburbans have four-wheel antilock disc brakes and stability control.Perhaps more than any other mechanical aspect the brakes were the biggest improvement on the 2007 resdesign.Although 2500s have stronger brakes they weigh more and have heavier-duty tires so they don't stop any quicker.Like any vehicle with ABS, press the brake pedal as hard as you can and steer and disregard and buzzing noises or vibration; that means it's working and is your best way to avoid an obstacle or accident.

Guiding a Suburban is effortless, the steering nicely weighted and direct by truck standards.At 18.5 feet long and 6.5 wide the Sub isn't ideal for congested areas but it's quite maneuverable for its size; it needs 43 feet of road to make a U-turn (45.5 for 2500), but that's just a yard more than some two-seaters and small sedans.So pretty good, in other words.And because of its boxy shape the corners are reasonably well defined; available rearview cameras and park sensors make it easier to parallel park but it won't drop right in.A new blind spot alert system optional on LTZ models adds a warning if you didn't see the vehicle next to you; like all such systems it focuses on your car and not what might be next to any trailer you're towing.

Suburban's 130-inch wheelbase and nearly 3-ton weight contribute to good ride quality, one of the best for any vehicle with a solid rear axle that doesn't employ air suspension (such as the Lexus LX570).The Expedition EL, Armada and Sequoia all have independent rear suspension that enjoys an advantage on rough roads and spirited driving.Some believe you must have a solid axle for towing and they are a bit easier to maintain, but extreme-duty vehicles like the Humvee and Mercedes Unimog successfully used independent rear suspension.In any case, the Burb has the traditional setup for towing.

Autoride suspension is available on some models.It monitors the road surface and driver inputs and adjusts damping as needed, optimizing the blend of ride comfort and handling grip, and also limits body roll in heavy cornering.The self-leveling rear suspension aspect of Autoride might help while towing but it is no substitute for a proper weight-distributing hitch.

The 2500 Suburban has different feel than the 1500 but drives through the same controls.Since it is designed for heavier use, carries about 500 pounds more and tows about 1500 pounds more the bits underneath are more truck-like.It has a much stronger rear axle with a shorter ratio, Chevrolet wisely thinking 2500 owners will prioritize towing performance over empty highway fuel economy.The front suspension uses torsion bars and the rear leaf springs rather than the 1500's coil springs.

All these parts add weight so the 2500 rides a little bit firmer and isn't as quick to turn as the 1500 but it is still a very competent chassis and at full load feels like it rides and handles at least as well as a loaded 1500.Were we regularly towing 6000 pounds, or 5000 with the family and gear onboard, we'd opt for the 2500 and its stouter running gear, expecting to give up no more than 1 mpg to a 6-liter 1500.Think of a Suburban 2500 as a three-quart-ton pickup with an enclosed bed and no window or seam in between.

And the leaf spring rear-end on the 2500 allows a significant increase in fuel capacity, from 31.5 gallons on the 1500 to 39 on the 2500, meaning the 2500 will travel further between fill-ups weaving your trailer through gas stations.

By default all Suburbans are set up for towing, but for larger trailers, say anything more than a twin-axle bass boat, consider opting for the trailer towing package (more engine oil and transmission fluid cooling), larger outside mirrors, and the integrated trailer brake controller carried over from pickups.Note that the controller may not work with electro-hydraulic trailer brakes as on some higher-end RVs; so consult your dealer.But a Suburban with this package is a fine tow vehicle, indeed.We've done major cross country tows over frozen highways and the Suburban performs admirably in this type of duty.

G.R.Whale reported to NewCarTestDrive.com from Southern California.