Our test truck was the Sonoma SLS 4X4 extended cab. It came with the $256 Heavy Duty Suspension Package that
includes heavy duty springs and shocks. It also came with an optional $1,802 package that included the Wideside
body, SLS sport decor, the Vortec 4300 V6 engine, aluminum wheels, air conditioning, tilt steering wheel, cruise
control and an AM/FM/cassette stereo with a clock. And it was equipped with dual lighted visor mirrors,
cupholders, and full floor carpeting with mats.
The Sonoma is an attractive truck with a smooth, aerodynamic hood that wraps around the front end. Its
exterior lines are now cleaner with a redesigned body-colored front bumper, fascia and grille and a new headlamp
design that integrates all forward lighting functions. Composite headlamps are standard with optional integral
fog lamps. The front license plate bracket is now molded into the charcoal- colored lower valance. A new center
step cutout in the rear bumper gives easy access to the cargo area and increases towing capacity on some models.
Maximum towing capacity is 5,500 pounds when equipped with a 4.3-liter V6 engine, automatic transmission, a
3.42 or 3.73 ratio axle and an aftermarket weight distributing hitch.
The stiff, four-sided ladder-type frame dips in the center to make it easier to step up and step down when
getting in and out without sacrificing ground clearance for off-pavement driving. The stiff frame allows the
suspension to do its job properly for improved ride quality and better handling.
Now a popular choice, the third-door option for extended cabs was an industry-first for compact trucks when
GMC introduced it. A driver's-side panel swings out to make it easier to load personal gear, pets and people.
Buyers of two-wheel-drive Sonomas have a choice of three types of suspension tuning: Smooth-Ride for a
sedan-like ride quality, Heavy-Duty for maximum payload and towing capability and Sport for the sharpest
handling response on paved roads.
The Sport, or ZQ8, suspension package for two-wheel-drive regular and extended cab models is designed for
performance enthusiasts. This street suspension package enhances handling and goes a long way toward making
the Sonoma ride and drive like a car. This is accomplished using shorter springs, high-performance gas shock
absorbers, urethane bounce jumpers, front and rear stabilizer bars, specially tuned variable-ratio power steering and wide eight-inch aluminum wheels with Goodyear P235/55R-16 tires. An optional locking rear differential enhances traction on unpaved roads.
Buyers of four-wheel-drive models have a choice of four suspension packages to suit their needs: Smooth Ride, High Payload, Off Road and Highrider. Distinctions include shocks, springs, and the wheel and tire package.
The Sonoma's interior is roomy, comfortable and functional. The long, wide body along with a thinner door
design translates to greater shoulder, hip and head room. For '98, there is new front door trim with wider
armrests and a cupholder integrated into the map pocket.
Seat options include high-back bucket seats for two passengers or a standard bench seat or reclining 60/40
split bench for three. Seat comfort has been improved with fabric enhancements, two-way driver lumbar and
standard recliners on SLS models. Seats, as well as door panels and carpet, are a Scotchguard stain-resistant
fabric.
The instrument panel is newly styled with improved ergonomics, including radio and ventilation controls that
are angled 15 degrees toward the driver for improved accessibility. Also new are a gauge cluster, backlit
headlamp switch, individual air-conditioning outlets with shutoff controls that completely stop air flow, and
a passenger-side assist grip located on the instrument panel. Up-level models now have two dash-mounted power
outlets below the ashtray.
Also redesigned is the center console, which can accommodate an optional remote cassette player with dual
feedback, for models with bucket or bench seats. The shifter for the automatic transmission has moved to the
steering column while the shift lever for the 5-speed manual transmission has been moved to improve ergonomics
and shift effort.
Models vary with the number of comfort and convenience features. Sunvisors with extensions for additional
glare protection are a thoughtful addition. A glove box, door pockets and space behind the seats provide basic
stowage needs. Extended cab trucks offer fold-down jump seats for rear occupants, but this space is better
reserved for pets and packages.
Other options include power windows, door locks and dual outside mirrors, tinted glass, and an upgraded
remote keyless entry system.
Safety features include taller integral head rests and a new seat belt design that allows the belt to travel
with the seat for a safer, more comfortable ride for occupants of all sizes; daytime running lamps are standard.
The Sonoma offers good seating position, with good visibility and an open, airy feel. A sloping hood, narrow
A-pillar and unobstructed views to the rear make for good visibility in all directions. One complaint we have
is that the lever used to adjust the seat fore and aft sticks out and one of our shorter drivers kept banging
her leg on it.
We enjoyed driving the Sonoma 4x4. As expected, ride quality was a bit jouncy with the heavy duty suspension package--these trucks ride much better with a cord of wood in back. The suspension is at its best when traversing rough terrain, hauling a heavy load or pulling a trailer.
The V6 engine provided healthy throttle response across the power band, which made everyday driving enjoyable and assisted with passing maneuvers. Sonoma's two V6 engines were upgraded last year with sequential central port fuel injection and offer an excellent combination of horsepower and torque. Our Sonoma 4x4 served up a robust 190 hp at 4400 rpm and 250 lb.-ft. of torque at 2800 rpm.
The base 2.2-liter four-cylinder engine, standard on two-wheel-drive models, has a number of enhancements for '98 that improve its mid-range torque and boost power to 120 hp at 5000 rpm and 140 lb.-ft. of torque at 3600 rpm. Torque is up significantly over the 1997 engine. Our STS was equipped with an electronically controlled four-speed automatic transmission with overdrive, a $1,070 option.
Sonoma's electronic transfer case called Insta-Trac is a dream to operate. Simply push a button to shift into low-range and you're ready for the toughest terrain. A high ground clearance, a locking differential, aggressive tires, gas-pressure shocks and heavy-duty multi-leaf rear springs produced positive results during our off-road excursions. The Off Road Package is designed for serious off-roaders. Four-wheel disc brakes come standard on four-wheel-drive models.
We particularly enjoyed the feel of Sonoma's improved brakes. Brake pedal travel is reduced with improved pedal feel, all of which instills confidence. They offer shorter stopping distances, better high-altitude performance and wear longer.