GM Ups Mediums
General Motors has significantly enhanced its medium-duty offering with the first factory-produced crew cab for the GMC Top Kick and Chevy Kodiak. The stylish cab is available across the medium-duty range from Class 4 through light Class 8 models. Also, the same frame that is under these conventional C-Series trucks is now under the Isuzu-cab T-Series Class 6 and 7 cabovers, offering greater component commonality across the medium truck ranges.
Conventional Crew Cabs
The crew cab option for the conventionals greatly enhances their usefulness in applications such as fire, forestry, landscaping and utilities, where crews are dispatched. It also makes the GMC and Chevrolet truck models very attractive in the vehicle recovery markets where stranded motorists and their families can be transported along with their cars.
Unlike other recent crew cab introductions, the GMs have a purpose-designed rear door for improved appearance and access. The cab's attractive trim includes a full-length headliner, heat-blocking solar ray tinted glass and extra storage space in the step wells.
The cabs feature revised sealing for the through-bulkhead doghouse resulting in a significant 50% reduction in noise, vibration and harshness. Powerful climate control systems are standard and a range of high-quality Delco audio systems and amenities like large cup holders provide additional comfort and convenience. The crew cabs are available on all chassis, with gross vehicle weight ratings from 16,500 to 61,000 pounds.
There's a wide selection of wheelbase options and a range of gasoline or diesel engines that include a new Duramax 7800 in-line six-cylinder diesel and the Caterpillar 3126E in the C6500/7500/8500 lineup. The Duramax engine is designed for durability and low operating costs, says GM. The standard Vortec 8100, the segment's unique gasoline V-8, is available with 295 hp at 3,600 rpm and 440 lb.-ft. of torque at 3,200 rpm.
Allison 2000 Series transmissions are standard in GM's C6500/7500 Series; the Allison MD 3000 Series is standard in the C8500 single-and tandem-axle models. Optional manual transmissions include a range of Eaton 5-, 6-, 9- and 10-speed models and two TTC 7-speed models.
T-Series Cabover
The switch from an Isuzu to a General Motors C-Series frame allows the new T-Series to accept a wide range of common truck bodies. At the same time, a longer setback to the front axle allows for wider steps and better access to the cab.
This truck's cab, chassis design and engine are the result of GM's global partnership with Isuzu, says the company. On the outside, there's little difference between the new GM T-Series and its predecessors, since the cab is largely unchanged.
However, a four-inch setback for the front axle has allowed for a much more generous lower step and a virtually straight-up climb into the cab. This change is unique to the GM products; Isuzu's big trucks continue with the shorter step.
The T-Series no longer has a Caterpillar option. However, the in-line Duramax 7800 features several horsepower ratings, from 200 hp to 250 hp and 275-300 horsepower versions will be released in early 2004. The engine delivers multiple torque outputs, from 520 lb.-ft. to 800 lb.-ft., to suit customer needs.
On The Road
We had an opportunity recently to drive the latest GM truck introductions and noticed immediately that the C-Series is a lot quieter than previously. We also found it features a tighter turning radius for better in-town maneuverability.
The cab is generously proportioned and the back seat — out of the passenger Savana/Express vans — provides generous legroom and a comfortable rake to the backrest. The cab rear doors are an interesting design, since they are the same pressing left and right. They only differ in the punching of the door handle opening, allowing for the design of a stylish cab and minimum of tooling for the rear doors. The cab can accommodate up to six adults in comfort.
As in regular-cab C's, the dash and instrument panels are straight out of the smaller vans, which is to say, decidedly "automotive" in design. Gauges and switches are very easy to see and use, even if they are not big-truck-like in styling. This goes for the steering wheel, too; it's what you'd find in GM's vans and pickups, and seems too small for a "serious" medium-duty truck, but works fine nonetheless.
The revised T-Series has an Allison transmission standard and, with excellent visibility of the cabover, is a simple truck for even a novice delivery driver to handle. We found it exceptionally quiet, comfortable and well equipped. Particularly noteworthy were its compliant ride and, with a cabover's shorter wheelbase, a turning radius even shorter than that of the C-Series.
