Blazes the trail with engineering advancements.
by Sam Moses
Base Price (MSRP) $25,755
As Tested (MSRP) $34,330
In the midsize SUV segment, Chevrolet has long been frustrated, watching Ford steal the show with the Explorer. The 2002 TrailBlazer is Chevy's best shot at reversing that order. It's a total redesign, including a stunning new straight-six engine, stiffer and lighter chassis, sophisticated suspension, powerful brakes and impressive details. The vehicle's 40-month planning and execution was done in a careful, creative, thorough and extremely bold manner. According to GM engineers, the TrailBlazer exceeds all the targets that had been set for it. Based on the specs and early performance, that claim is easy to believe.
There are three models of TrailBlazer: LS, LT and LTZ, which come either as 2WD or electronic 4WD.
All TrailBlazers have four doors and come with the new 4.2-liter inline six-cylinder engine and four-speed automatic transmission.
Standard equipment on all models are dual-stage driver and passenger airbags (activating with less intensity in slower crashes) plus seat-mounted side airbags in front, in addition to steel door beams.
A complete tow package is also standard, including a hitch platform with seven-pin wiring for trailers with brakes. The standard final drive ratio is 3.73:1, with 4.10:1 available for more responsive towing and 3.42:1 for higher gas mileage. However the estimated EPA rated mileage of 15/21 mpg city/highway is based on that optional 3.42 rear end (a legal EPA loophole) so “higher” is relative.
Some options on the LS that are standard on the LT and LTZ include remote entry, cruise control, rear defogger, cargo cover, carpeted floor mats, heated mirrors and GM's OnStar security system with GPS tracking and cell phone communication, including emergency assistance and remote unlocking. Options on the LT and LTZ that are unavailable on the LS include 2WD traction control, running boards, six-disc CD changer and Bose sound system.
Unavailable on the LS are foglamps, rain-sensing wipers, rear heat controls, leather interior, power heated seats, Driver Information Center, rear seat radio controls with headphone jacks, and 17-inch wheels. About the only things you can get on the LTZ but not the LT are heated/memory seats, rain-sensing wipers and 17-inch wheels.
Skid plates for the transfer case and fuel tank, sliding electric sunroof and locking rear differential are options on all three models.
The styling is fresh, while still being very consistent with the Chevy truck line: the front end looks like a scaled-down Suburban or Silverado. The trademark bowtie in the center of the bar across the grille is chrome on the LS, body-colored on the LT and LTZ. The bumper under the grille has a large opening with two vertical slats, and the optional foglights are mounted down low.
At the rear, there's a convenient and practical step in the center of the rear bumper, sort of a big notch. But styling-wise, the twin round taillights stacked over the backup light at each corner are kind of lumpy and googly-eyed.
Overall, it looks sturdy and neat, with confident lines that express utility. The pillars and window lines are graceful, while the headlamps (split by the grille crossmember), taillights and turn signals are stylish. Big fender flares are used to visually express the vehicle's boldness, and may be either monotone or silver.
The most dramatic thing about the TrailBlazer may be what's not there: neither a V6 nor V8 engine. The new engine is called the Vortec 4200, an all-aluminum, double-overhead-cam, 24-valve inline six with variable valve timing.
Years ago Chevy trucks used an old reliable straight six, and Jeep has long used a more basic straight six in the Cherokee, while BMW and Lexus continue to use sophisticated versions in high-performance sedans. An inline engine is inherently smoother, simpler, more durable and more fuel efficient than a vee, although in times past, its superior physics had a hard time breaking out of its cast-iron shell. Advancements in electronics, metallurgy and manufacturing methods now enable an inline engine to soar, and for 2002 GM has fully exploited this technical opportunity.
The Vortec 4200 is no ordinary straight six. From 4.2 liters, it produces a stunning 270 horsepower, 30 more than Ford Explorer's new 4.6-liter sohc V8. And it has a very broad torque curve peaking at 275 pounds-feet, only 5 less than the Ford and coming 400 rpm sooner. It features electronic throttle control, an electrical system using silicon circuit boards (replacing some 1100 feet of copper wire), coil-on-plug ignition (thus no plug wires), and a seven-quart oil pan with a clever tunnel for the front drive axle, which allows the longish block to be mounted six inches lower, contributing to better balance and a lower center of gravity.
Attention to detail in other places is evident, from a battery box that draws in cooling air, to remarkably sanitary wiring under the hood, to rear-seat headrests that conveniently flip down for better rearward driver visibility. Because the engine is so quiet and smooth at idle, a feature called “intellistart” was added which prevents the starter from grinding if the key is turned when the engine is already running. With a mixture of amusement and pride, GM engineers report that this happened to them all the time during development.
The Autotrac system, standard on 4WD models, features four settings: 2WD, Auto4WD, 4HI and 4LO. In Auto, which shifts power to all four wheels as conditions require, the TrailBlazer can be towed without having to disconnect the driveshaft-a very convenient new feature. Switching in and out of 4WD can be done on the fly with a flip of the switch, although the vehicle must be in neutral to engage or disengage 4LO.
The chassis and suspension are also highly developed, featuring a list of sports car stuff: rack-and-pinion steering, beefy four-wheel vented discs with twin-piston calipers in front, independent front suspension with short/long control arms, solid rear axle using five-link suspension with Bilstein gas-charged shock absorbers and coil springs, thick antiroll bars front and rear. It was the first truck for the TrailBlazer's chief designer, Ted Robertson, who brought a resume to the assignment that includes the '90s Camaro/Firebird. GM wanted his soul as well as his experience in their midsize SUVs, and they got it. His approach was to put some “sport” in Sport Utility.
The TrailBlazer is 8.3 inches longer and 6.9 inches wider than the current Blazer. The track (the distance between the left and right tires) is the widest in class, 2.2 inches wider than the 2002 Explorer (also redesigned) in front and 0.9 inches wider in rear, with a very tight turning circle of 36.4 feet, achieved by the wheels being able to turn more thanks to the suspension design and engine location.
Finally, the chassis rails are shaped by hydroforming, a process pioneered in the '97 C5 Corvette that makes the rails stronger and lighter. No less than eight crossmembers contribute to a claimed 260 percent increase in torsional rigidity, and there are 12 tuned body mounts made of urethane.
All TrailBlazers seat five passengers, compared to the Explorer's optional seven seats on a nearly identical wheelbase, with its third row of seats squeezed in (the five-seat Explorer has 10 percent more cargo space, thanks to a lower cargo floor enabled by its independent rear suspension). A seven-seat TrailBlazer with longer wheelbase is in the works. GM says their buyers told them that seven passengers on a five-seat wheelbase didn't appeal to them. So GM will build a separate chassis.
For leg room, the TrailBlazer offers 44.6 inches in front (0.7 more than Explorer) and 37.1 inches in the rear (0.1 inch less). Working with a vehicle width that exceeds the Explorer by 2.5 inches, the TrailBlazer's rear seats offer slightly less shoulder room but 3.8 inches more total hip room.
The seats come standard in fabric (LS), cloth (LT), and rich-feeling leather (LTZ); adjustment is manual in LS and gains in trickery all the way up to eight-way power operation with memory (including outside mirror adjustment) and optional heating on the LTZ. The front buckets are designed to accommodate heights ranging from 4'10” to 6'2”, but there is a noticeable lack of side bolstering. The front seats don't do justice to the ride, allowing the occupants to feel a side-to-side jouncing that doesn't exist in the 2002 GMC Envoy with the same chassis and suspension but better seats.
Interior lights abound, including reading lights. GM calls the interior lighting “world class,” developed by the Rensselaer Polytechnic Institute Lighting Research Center in Indiana.
The instrumentation is complete and clean. A big tachometer is on the left, speedometer in center, and on the right are smaller gauges for water, battery, gas and oil. Brushed nickel is the basic trim, while wood comes with the leather interior. The four-spoke leather-wrapped steering wheel (standard on LTZ, optional on LT) has eight buttons, for climate, sound, cruise control and driver information center in eight languages.
The console includes an open storage bin, an enclosed compartment and two cupholders forward of the gear lever (plus two more for the rear passengers). There are pockets in the front doors and behind the front seats, though none in the rear doors. Standard behind the rear seat is a small hidden compartment under the floor, while optional features include a cargo net, scrolling tonneau cover and power outlet.
The overhead console includes a standard sunglasses holder, plus Travelnote digital recorder (optional with LS, standard with LT and LTZ), which might be considered an important safety feature, as it allows the driver to orally take phone numbers while on a cellphone, thus keeping at least one hand on the wheel. Heating and air conditioning can be controlled separately by the driver, front and rear passengers (which might be considered a safety feature because it too allows the driver to keep both hands on the wheel, instead of having to use one to fight with his passengers).
Depending on the trim level, the sound systems include radio/CD, radio/CD/cassette, six-disc in-dash CD, or six-speaker 275-watt Bose system. Our test model was equipped with the Bose, offering outstanding sound quality and adjustment versatility. All the systems include RDS (Radio Data Systems) technology, allowing the listener to search for stations by type, display information including song and artist information, and provide traffic and weather updates. Rear seat controls and headphone jacks are standard with LTZ, optional with LT and unavailable with LS.
The OnStar communications system is standard with LT and LTZ, optional with LS. It includes GPS navigation, hands-free cellphone communication including free first year safety and security service-automatic crash and theft reporting, as well as remote unlocking if you lock yourself out. Mind-boggling possibilities include everything from having your email read to you by a computerized voice (“Virtual Advisor”) to getting directions to the nearest ATM.
Also available is a rear seat DVD entertainment system, with a seven-inch flip-down screen and wireless headphones.
General Motors introduced the TrailBlazer and its two other midsize SUVs, the GMC Envoy and Oldsmobile Bravada, to the world's automotive journalists in Baja in December. Based on about 100 miles of driving on rough and fast Mexican two-lanes-flat and climbing, straight and twisting-and a few laps around an off-road course with steep climbs and descents and 50-mph washboard trails, the TrailBlazer might very well be as much truck as any SUV has ever been, and more car than any SUV has ever been-at least for the price. It eliminates the compromises. It is totally rugged and capable, while being totally comfortable and civilized.
If you didn't know what kind of engine was under the hood, you might wonder. “Hmm - this couldn't be a V6, too much power. It has the torque of a small overhead-cam V8 - but it sure doesn't sound like one.” It's so smooth that it doesn't sound like much of anything. And the faster it goes, the smoother it gets. With an official Mexican Highway Patrol escort along on the test drive, we felt free to briefly run the TrailBlazer up to 100 mph, and it was above 80 where the inline engine really showed the silky side of its character.
It showed the beefy side down low. Our LTZ test model was equipped with the optional 4.10 rear differential, and was able to blast past Mexican trucks on steep uphill two-lanes with calm confidence. It leaves the surge in while taking the jerk out, because the burst of acceleration often comes without a downshift, as the ample low-end torque doesn't need it and therefore the four-speed automatic transmission isn't programmed for it. Ninety percent of the peak torque of 275 pound-feet is there at 1600 rpm-and it's still there at 5600 rpm. The full-throttle upshift comes at 6000 rpm, and the engine is still only striding, not screaming.
The smooth-shifting transmission is the proven Hydra-matic 4L60-E, used in GM applications from Corvettes to Cadillac Escalades.
Towing was a high priority with the TrailBlazer, which is rated at 6400 pounds on 2WD models, 6200 pounds on 4WD models. In Baja, the engineers couldn't stop raving about its capability. With genuine excitement (and glee), they boasted that during their own comparison testing, a TrailBlazer “ran away and hid” from a Jeep Grand Cherokee V8 in a trailer-pulling race up a mountain. They added that it ran way cooler (thanks in part to that big seven-quart oil pan) and used 20-percent less gas. They didn't say which rear end it had, the 3.73 or 4.10, but they did claim that towing would be no problem even with the long-legged 3.42.
By the way, added chief engineer Ted Robertson, there's another 30 horsepower to be had just by going to dual exhausts. Aftermarket manufacturers are probably bending pipes now.
On the stopping end, all you really have to do is look at the discs. There are four of them, all ventilated, and they are big: the front rotors are 12.0 inches and the rears 12.8, with a total swept area of 424 square inches. In addition, the aluminum front calipers are twin-piston. Four-wheel ABS is standard. Under hard braking, we especially noticed that the TrailBlazer's nose didn't dive, keeping the vehicle remarkably level and stable.
Because the vehicles in Baja were pre-production, there were some suspension discrepancies that taint any specific observations of the ride and handling-most notably, as Robertson himself only discovered near the end of the test, the rear coil springs were not the correct stiffness. Still, the ride was excellent, very smooth: in a word, carlike, without being too soft. It was designed to roll exactly five degrees in the corners, and then stop leaning. The amount of lean is often precisely selected and engineered, depending upon the anticipated buyers for the vehicle, and in this case Robertson chose that degree for a margin of comfort and security. As with horsepower, sometimes high-performance handling can get average-skilled drivers in trouble.
The track is the widest in class, 2.2 inches wider than the 2002 Explorer in front and 0.9 inch wider in rear. This, coupled with a lowered mass from the engine position, drops the center of gravity. This could be a strong selling point, as the big issue with SUVs nowadays is their higher incidence of rollovers than sedans.
Among GM's three midsize SUVs, including the GMC Envoy and Olds Bravada, “The TrailBlazer is the one for off-road,” said Robertson-it's the least luxurious and has the less-compromising coil-spring rear suspension, which, theoretically at least, keeps the rear wheels planted more firmly. We found that to be true on the offroad course, as the TrailBlazer was uncommonly and impressively stable on the high-speed washboard portion.
It bottomed quite easily on the dives, however, signaling that the optional skid plates are necessary for offroading. Our test model (equipped with 17-inch BFG Rugged Trail radials) had the skid plates, of course, which we also dragged in soft sand, chugging easily along at 5 mph in Auto4WD. Here is where the compromise appears to be buried. The bottoming was partially caused by a slightly low eight-inch ground clearance under the engine, a result of that clever tunnel through the oil pan for the front driveshafts, allowing that lower engine mounting for better balance on the road. But a ground clearance that's 1.2 or 1.3 inches lower than the competition (Explorer, Grand Cherokee) seems a reasonable and maybe even prudent payoff.
Another problem that appeared offroad, on two out of three short sessions, was a horrible squeak from the front rotors after they had passed through sand, mud and weeds-we even heard it once on another vehicle that hadn't been offroad. There's apparently something in the design of the brakes or calipers that allows debris to lodge in there. However it might be easily cured-and may have been, in the two months between this introduction and vehicle production at its plant in Moraine, Ohio.
“Maybe we can even convince people that we're not the same old GM,” said Ron Kociba, chief designer of the stunning new engine. At the pivotal meeting when he proposed building an inline six to top GM executives, one of them responded, “Maybe this is an opportunity to distinguish ourselves from the rest.” The 2002 TrailBlazer has already done this. Redesigned from the ground up, along with the Envoy and Bravada, it redefines the state of the midsize SUV art.
© New Car Test Drive, Inc.