General Motors introduces a number of significant enhancements to its medium-duty model lineup for the 2007i and 2008 model years. These include an all-new Chevrolet and GMC W-Series, as well as revised diesel engines and exhaust systems to ensure GM medium-duty trucks meet new, more stringent federal and state of California diesel as emissions standards. All-new W-Series
The Chevrolet and GMC W-Series is all new for 2008, with a larger and more spacious cab that provides more side-to-side and front-to-back room on both standard and crew cab models. The all-new W-Series also features a new, more modern dashboard with a full complement of easy-to-see gauges and warning lamps. It includes a 5-din opening for such optional equipment as radios, GPS systems and rearview cameras. The front of the cab features an easy-to-remove panel for easy access to the wiper motor and linkage, electrical cab connections and air intake filters, facilitating maintenance of these items. Storage areas abound in the 2008 W-Series, including in the seat backs, dashboard, glove box, overhead storage shelves and rear storage organizer. The all-new cab has greater rust and corrosion protection from the galvanized steel panels to the electro deposit paint primer and high quality enamel paint top coat. The close section and increased gussets and reinforcements also improve the durability of this new cab, as well as increasing the safety of the driver and passengers. Additional safety items found on the 2008 Chevrolet and GMC W-Series include: a new seat belt design; low-cut side windows; larger, 17-inch by 8-inch side mirrors with integrated convex sections; and available heated mirrors. W-Series longer wheelbases
W-Series customers looking for long-wheelbase low cab forward trucks need look no further than the 2008 W5500 and W5500 HD LWB models. W5500 22-foot models are now available with a 200-inch wheelbase – 24 inches longer than the previously longest wheelbase of 176 inches. For customers requiring an even longer wheelbase, W5500 HD 22- and 24-foot models are available with a 212-inch wheelbase. W5500 and W5500 HD LWB models are powered exclusively by the overhead cam 5.2L 4HK1-TC turbocharged, intercooled, diesel engine. It delivers 205 horsepower and 441 lb.-ft. of torque and is mated to a new Aisin A465 heavy-duty six-speed automatic with double overdrive. Chevrolet and GMC W5500 and W5500 HD LWB models are ideal for companies that transport furniture and appliances, as well as bakers, florists and heating and cooling companies. W-Series Onyx Edition
Chevrolet and GMC offer the 2008 W-Series Onyx Edition, a fully loaded truck with a host of special features, including an air deflector; stainless steel wheel simulators; air conditioning; AM-FM CD player radio; unique, rich, all-black exterior Onyx paint with classic silver highlights; a custom stripe; and silver and gray decals. The Chevrolet and GMC Onyx Edition are based on a 14,500-GVWR, 132-inch wheelbase, 14-foot body W4500 model and are powered by the 5.2L 4HK1-TC turbocharged, intercooled, diesel engine. Power is transferred to the wheels via the new Aisin A465 heavy-duty six-speed automatic with double overdrive. W3500 Gas Crew Cab
Another addition to the Chevrolet and GMC W-Series lineup is the W3500 Gas Crew Cab. It combines the added interior room of a crew cab with the power and convenience of a gasoline engine. The W3500 Gas Crew Cab will appeal to medium-duty customers who typically put less than 30,000 miles on their vehicles annually. Likely applications include landscaping services, furniture transport, construction and much more. The W3500 Gas Crew Cab will be available later in the model year and will be powered by the 325-horsepower Vortec 6.0L V-8 engine that is mated to the Hydra-Matic 4L80 four-speed automatic with lockup torque converter and overdrive. T-Series
The legendary Chevrolet and GMC T-Series value is further accented for the 2007i model year by a number of improvements to the Allison transmissions. The Extended Service Coverage on Allison 2200 HS and the 2500 HS transmissions increases to four years with unlimited miles. Previously, the service coverage was for three years. Both transmissions are now six-speed with a second overdrive ratio to improve driveability and fuel economy. The Allison 2200 features a close-ratio design, a park pawl and is rated for a maximum GVWR and GCWR of 26,000 lbs. The 2500 HS features a wide ratio design without a park pawl and is rated for a maximum GVWR/GCWR of 33,000 lbs. Factory-fill TranSynd transmission fluid is required by Allison to allow the longer Extended Service Coverage. TranSynd can also extend Allison transmission oil drain intervals up to 400 percent, further reducing vehicle downtime. Other Allison vocational transmissions available on the Chevrolet and GMC T-Series include the 2200 and 2500 RDS on Class 6 and Class 7 models. The Allison 3000 RDS close-ratio six-speed automatic transmission is standard on Class 8 models and is available on Class 6 and Class 7 models. Available on all T-Series models are Allison 3500 RDS, 3000 EVS and 3500 EVS transmissions – offered in five- and six-speed versions. All of these transmissions include Gen IV controls for smoother shifts. T-Series customers may also equip their vehicles with an Eaton-Fuller manual transmission available in six-, nine- or 10-speed (8+2) configurations. C-Class
Smoother-shifting transmissions – many with extended service coverage – lead the list of product enhancements on 2007i C-Class. Allison 1000 HS and 2500 HS (Highway Series) now feature a four-year, unlimited mileage warranty. The 1000 PTS and the 2200 PTS (used in school and shuttle bus applications) transmissions now feature a four-year, 100,000-mile service coverage (versus three-year, 100,000-mile warranty for 2006). The Allison 2200 PTS – when used in school bus applications – features a five-year, 100,000-mile service coverage. That is two years longer than the 2006 warranty. As is the case with T-Series transmissions, factory-fill TranSynd transmission fluid is required by Allison to allow the longer service coverage on C-Class transmissions. Additional Allison transmission enhancements for 2007 include Gen IV controls – for smoother shifts – on C6500, C7500 and C8500 models and new, six-speed Allison 1000 MH, 2200 MH and 2350 MHE (general truck), MHD (fire and emergency) and MHF (motor home) transmissions with a 0.61:1 overdrive gear ratio on select C4500 and C5500 models. The Allison 2350 allows GCWR of 30,000 pounds and features double overdrive, torque converter clutch and park pawl. In addition, the Allison 2550 is available on C6500 and C7500 models, as well as on T6500 and T7500 models and offers a wide artio 6-speed transmission rated at 30,000 lbs. GVWR and GCWR with an integral park pawl. Diesel engines
For 2008, the W-Series overhead cam Isuzu 5.2L 4HK1-TC turbocharged, intercooled, diesel engine delivers more power and reduced emissions. Horsepower increases to 205 at 2400 rpm (up from 190) and torque increases to 441 lb.-ft. at 1850 (up from 387). It covers GVW ranges from 12,000 pounds to 19,500 pounds and has a B10 durability rating of 310,000 miles, which means 90 percent of the engines should reach this mileage before a major component failure – provided good maintenance practices have been followed. The 5.2L diesel engine is equipped with a standard fuel/water separator that is heated with returned fuel and features a dash-mounted warning lamp. This separator warns the driver when water is present in the fuel filter and needs to be drained, which helps prevent vehicle down time and supports a more efficient operation. The 5.2L diesel engine can be mated to the new Aisin A465 heavy-duty six-speed automatic with double overdrive or to a six-speed manual transmission with all forward gears synchronized. The six-speed manual will be available later in the model year. The Isuzu 6H diesel engine – the base diesel engine in all Class 6 and 8 models – has been updated to meet 2007 emission standards that went into effect on Jan. 1. It's also more powerful, with the base rating increasing to 215 horsepower and 560 lb.-ft. of torque – a 7.5-percent increase in both horsepower and torque over the 2007 models. The 6H engine is available in five horsepower and torque ratings, including a maximum of 300 horsepower and 860 lb.-ft. of torque, and has a B10 durability rating of 410,000 miles. All 6H engines feature an integrated oxidation catalyst, diesel particulate filter and GM's patented exhaust gas cooler. Higher-output versions of the engine feature a larger-capacity DPF. C4500/5500 models feature the Duramax 6.6L engine that has been significantly revised to meet 2007 diesel emission standards. (See "Diesel emissions regulations" section below for greater details.) The base diesel engine models feature 300 horsepower with 520 lb.-ft. of torque; a 330-horsepower with 620 lb.-ft. of torque rating is available for applications such as ambulance, towing and motor home. C6500/7500/8500 models are available with an optional Caterpillar C7 (7.2L diesel I-6) that delivers a wide range of horsepower ratings – from 207 to 250 – and torque ratings ranging up to 800 lb.-ft. The C7 engine features Caterpillar’s ACERT Technology to meet 2007 emission standards. This technology reduces emissions at the point of combustion by capitalizing on Caterpillar's expertise in four core engine systems: fuel, air, electronics and aftertreatment. Gasoline engines
For Chevrolet and GMC W-Series customers who prefer a gasoline engine, W3500 and W4500 models are available with the Vortec 6.0L V-8 engine. For 2008, the Vortec 6.0L engine delivers 325 horsepower – 25 more than the previous version – and 360 lb.-ft. of torque. These models are mated to the Hydra-Matic 4L80 four-speed automatic with lockup torque converter and overdrive. The Vortec 6.0L is 50-state compliant with federal CFFV/LEV and California ULEV emissions requirements. It has a 200,000-mile design life and is backed by a three-year/36,000-mile warranty. Customers may also purchase extended service plans that cover their vehicles for up to five years/100,000 miles. Kodiak and TopKick customers may also opt for the Vortec 8100 MD (8.1L V-8) engine. It delivers 295 horsepower and 440 lb.-ft. of torque in C6500-C8500 models, and 325 horsepower and 450 lb.-ft. of torque in C4500 and C5500 models. The Vortec 8100 also features 200,000-mile design life and is backed by a 2 year unlimited mile warranty. Diesel emission regulations
All diesel engines meet the Environmental Protection Agency (EPA), requirements that became effective for diesel engines manufactured after Jan. 1, 2007. These regulations compel all diesel engine manufacturers to reduce nitrogen oxide (NOx) and particulate matter (PM) emissions by 90 percent over the previous (2004) diesel engine standards. For the reduction of nitrogen oxide levels, the 5.2L, 6.6L and 7.8L diesel engines use an advanced exhaust gas recirculation (EGR) system and a variable geometry turbocharger. To reduce particulate matter, a ceramic honeycomb channel diesel particulate filter (DPF) was created to capture sulfate particles and soot. Exhaust gases are directed through the channels and a porous material that traps the particulates. To clear the particulates and prevent clogging, a regeneration process occurs to burn off the trapped particulates and clean the filter using high exhaust gas temperatures. Regeneration in GM medium-duty trucks can occur in a number of ways. Self-regeneration is an automatic process that occurs as the vehicle is driven throughout the day, and does not require driver involvement. The vast majority of vehicles will regenerate automatically. Forced computer-initiated regeneration occurs if the vehicle operation does not produce exhaust gases hot enough for the automatic process to occur. In the event that the computer cannot force regeneration, a control light will alert the driver to activate a dashboard switch to initiate the regeneration process. Special system-sensing and control software was developed to precisely control engine combustion and DPF regeneration. To meet the EPA regulation for lower diesel fuel sulfur emissions, GM-designed emissions systems work efficiently with the new fuels and lubricants. The 2007 emission regulations also require all crankcase gas emissions to be reduced. To comply, a closed crankcase system was added to reroute ventilation gases back into the engine for combustion.