is on a mission. Finding themselves on the shorter end of the pickup truck
market stick, they are determined to not only rebuild their entire truck
lineup, but build the best trucks on the market period. That's a tall order
these days in this highly competitive market, but from what we have seen
and driven so far, you would be foolish not to take them seriously.
For those that may have not have been keeping score, GM started its rebuilding
process in 1999 with the launch of the new half and three-quarter ton pickups.
In 2000 GM introduced all new full-size sport utilities and for 2001 the
new heavy-duty full-size pickups round out the offerings. GM plans to sell
more than 250,000 heavy duty units in the 2001 model year and has spent
an enormous amount of time going back to the customer base in search of
the right changes and improvements. Customers demanded great driver and
passenger environment, affordability, a well-built, safe and secure vehicle
and most importantly a "a truck that looks like a truck". GM then
set out to create class leading powertrains, payload capacity, towing and
GM now leads the entire class (at least this month) with the most powerful
gasoline and diesel engines available. All new powertrains are validated
for an operating life of at least 200,000 miles without major component
failures. At the same time improving maintenance issues and improved economy
over their predecessors.
GM's new Duramax 6600 replaces previous the 6.5 liter turbo diesel. Developed
jointly with Isuzu Motors, this new powerhouse is a 90-degree, injection,
overhead valve, four valve-per-cylinder turbocharged V8, with aluminum high-swirl
cylinder heads and puts 300hp and 520 lb./ft of torque at 1800 rpm to the
crank. This puts the Duramax more than 65hp and 20 lb./ft above Ford's 7.3l
and more than 70hp and 70 lb./ft above the Dodge 5.9l diesel. What this
newfound power translates into is class leading pulling and hauling capability
while still achieving 19 percent better fuel economy over the outgoing 6.5
liter. GM lined up all the competition at the press introduction with 22,000lbs
GCW trailers with wind resistance screens to simulate towing a very large
motorhome. The first thing you noticed in the GMC and Chevy vehicles equipped
with the new Duramax diesel were how much quieter they were than any of
the competition (GM claims half as quiet as the Ford 7.3 liter). Through
the towing and hauling exercises, the new GM models had noticeably more
pep on steep grades while climbing hills than either the Ford or Dodge offerings.
Plus the new Allison transmission with grade braking are a gem with this
engine, but more on that later.
Also new for 2001 is the Vortex 8100, nearly 80 percent brand new over the
7.4l big block. The new Vortex 8100 shares its predecessor Vortex 7400's
valve and bore centers and bore diameter. But its stroke has been increased
by 9.4mm for a higher displacement and more power. With 340hp and 455 lb./ft
of torque at 3200, this new motor even edges out the power outputs of Ford
and Dodge's V10 models (275hp and 300hp respectively).
Even with this increased performance, mileage has improved 4 percent over
the 6.5 liter V8. The low maintenance design only requires oil and filter
changes during the first 100,000 miles, and coolant changes every 150,000
On the street this new big block V8 has impressive power, easily moving
a full horse livery trailer over the hills of Branson Missouri. Power delivery
is smooth and quiet with more than 90 percent of available torque at 1800
RPM. This new motor really moves off the line and won't leave you wishing
for more power when the need arises
The Vortex 6600 replaces the previous 5700. With 300hp and 360 lb./ft of
torque, the 6600 is the most powerful standard engine available in its class
with Ford trailing at 260hp and Dodge at 250hp. The 2001 Vortex 6600 features
cast-aluminum cylinders, shaving 55 lb. of weight in the process thus providing
more valve seat durability over the 5700 it replaces. Volumetric efficiency
has been improved with new exhaust ports borrowed from the Corvette, while
dual catalytic converters and exhaust pipes minimize back-pressure and provide
more power. What all this translates into is significantly more power in
the standard GM heavy-duty offering with improved fuel economy and even
To compliment the new engine lineup, GM has two all new units added to it's
existing transmission offerings for 2001.
First out of the block is the new smooth shifting, German made ZF S6-650.
This slick new six-speed manual transmission is the first of its kind in
this segment to be offered in both gasoline and diesel powered vehicles.
First gear is designed as a 'creeper gear' for better low-end performance
and towing. With reverse and first gear in the same shift gate, users can
throw the gear lever forward for reverse and straight back for first, which
should make snowplowing and low speed maneuvers a bit easier. Sixth gear
is positioned away from the seating area, giving more room to both driver
and passenger during extended highway cruising. This transmission is also
equipped with a PTO provision providing up to 25hp capacity.
Next up is the new Allison M74 1000 five-speed automatic. Allison is a leading
supplier of automatic transmissions for large application commercial truck
and bus markets. Taking those years of experience, they have supplied GM
with a great unit full of wonderful features.
Allison 1000 has full electronic control of shift timing. With fuzzy logic
programmed into its controls, the transmission provides a major new benefit
GM calls Engine Grade Braking®. If a driver descends a hill, the Transmission
Control Module (TCM) senses the weight of the load, the vehicle's speed
and the deceleration rate and automatically downshifts to a lower gear to
help slow the truck. In GM's proprietary Tow-Haul mode via a push button
on the transmission stalk, the Allison transmission will do multiple downshifts
from fifth to fourth and from fourth to third, using steadily lower gears
to help slow the decent. Tow-Haul mode also minimizes the amount of "shift-business"
as GM calls it while navigating large hills or under heavy towing conditions.
All this fuzzy logic actually works rather well in application, forcing
the transmission to downshift one gear just about the time we were going
to put a foot on the brakes to slow us down. Kind of creepy actually, as
it seemed to sense whenever we were about to brake downhill, firing off
another downshift. If you do any towing or heavy hauling, this is one transmission
you don't want to be without.
GM used hydroforming technology (again borrowed from the Corvette) in the
front frame rails of all models, increasing strength and stiffness. In addition,
the 3500 Series are the only chassis cabs in their segment to meet all of
the National Truck Equipment Association's requirements for quick, cost-effective
mounting of specialized bodies and equipment. They have clear, flat 34-inch
wide rails and a larger, standard 50-gallon dual fuel tank system.
A long and short-arm independent front torsion bar suspension is standard
on all models. It provides a smoother ride, greater durability, more on-center
feel and better stability over preceding models. Semi-elliptic multi-leaf
rear springs do duty in the rear. Front and rear track have also been increased,
giving yet more stability. On the road these new GM models were extremely
quiet, kept body-roll in check and rode exceptionally well for their heavy-duty
Four wheel discs featuring GM's Hydro-Boost brake assist system and four-wheel
ABS are standard on all models. Audible brake pad wear sensors have also
been added both front and rear.
Wheels and Tires
Wider standard 16 x 6.5 inch eight-bolt wheels are standard for 2001. Also
higher E-load range tires help provide for increased load-capacity. 2500HD
models feature 245/75R-16 radials with either all-season or on/off road
design, depending on the model. The 3500 Series have standard 215/85R-16
highway or on/off road radials. Full size spare is standard.
Hauling and Trailer Capability
With all the new found power improvements, improved chassis rigidity and
higher capacity brakes comes new payload capacities and increased towing
and hauling capabilities The 3/4 ton comes in at 9,200 pound GVWR (400 lb.
more than competitors) and payloads of up to 3,954 lb. The one ton pickup
is rated at 11,400 pound GVWR (200lbs more than Ford and 900 lb. more than
Dodge). Both the 8100 and Duramax Diesel V8 permit towing trailers weighing
up to 12,000 lb. and provide a maximum 22,000 lb. gross combined weight
The Silverado HD (pictured above) and Sierra HD have a new massive front-end
appearance that includes wider openings and bolder chrome accents. The hood
is elevated and front bumper pads thicker to accommodate a two-inch higher
body height. Integrated wheel flares add to a strong, aggressive appearance.
Dooley models feature a new one-piece composite rear fender that reduces
weight while adding durability. Cargo boxes have also been enlarged primarily
between the wheel wells giving an additional 2 percent increase over previous
Regular, four-door, extended and Crew Cab sizes have all been increased
over previous designs for significantly more interior room. The new Crew
Cab has 1.1 inches of additional head room and an extra 1.4 inches more
hip room up front. Rear seat passengers see an additional .7 inches more
rear leg room, .2 inches more rear shoulder room and 3.6 inches more rear
The Crew Cab's rear seat is a 40/60 split bench with room for three passengers.
The seat can be folded to create a large, flat surface that's ideal for
carrying luggage, tools or pets. With bucket seats, the Crew Cab also has
a center console with a large, lockable storage volume, two cupholders,
extra storage in the lid and coin holder. The rear of the console, like
that of the extended cab, also has two more cupholders, adjustable air conditioning
vents and a small storage bin for rear passengers. Depending on trim level,
an overhead mini or full feature console also provides additional storage
room on all models.
In addition, GM has announced the OnStar System will be standard on uplevel
Silverado LT and Sierra SLE extended cab and Crew Cab models. Dual airbags
are also standard on all models with a passenger side deactivation switch
on regular and extended cab models to protect small occupants.
The new Chevy Silverado and GMC Sierra each offer more than 32 heavy-duty
models including 3/4 ton (2500 series) and one ton (3500 series) regular
cabs, four-door extended cabs and chassis cabs, plus there are even special
versions available with reduced gross vehicle weight for alternative fuel
vehicles. With the extensive improvements made and the time taken to seriously
listen to customers requests, GM has moved ahead in the heavy-duty segment.
Superior engines, great transmission offerings and stellar performance in
all categories make a compelling story. This is one truck definitely worth
taking a serious look at.