NTEA members examine a new GM chassis cab.NTEA members examine a new GM chassis cab.

GENERAL Motors' compressed natural gas (CNG)-powered Chevrolet Express and GMC Savana full-size vans are “selling like hotcakes” and the GM plant “is full with our allotment of what we can do for the next three to four months,” according to Joseph Langhauser, vans and mobility product manager.

GM announced in May that it would be the only manufacturer to offer a one-source van CNG option, rather than on contracting the conversion of their vehicles. The vans will meet all Environmental Protection Agency (EPA) and California Air Resources Board (CARB) emission certification requirements, and will be fully compliant with applicable motor vehicle safety standards, Langhauser said.

Each CNG Chevrolet Express or GMC Savana van also will be covered by GM's three-year, 36,000-mile new vehicle limited warranty and five-year, 100,000-mile limited powertrain warranty.

Joe Langhauser of GM vans and mobility product manager The CNG vehicle begins with GM's Vortec 6.0L V8 engine. GM engineers modified it with hardened exhaust valves, and intake and exhaust valve seats for improved wear resistance and durability with gaseous fuel systems. These hardened engines will then be assembled into the Chevrolet Express and GMC Savana vans at GM's Wentzville, Mo. plant.

IMPCO Automotive is providing the “under-hood” CNG fuel system. IMPCO's production began earlier this year at its 75,000-square-foot OEM fleet conversion facility in Union City, Ind., which has been reconfigured into a high-volume conversion plant utilizing state-of-the-art manufacturing practices.

All vehicles comply with EPA: BIN 5 and CARB: LEV2 - SULEV emission requirements, certified in all 50 states.

Langhauser said GM will release its liquefied petroleum gas (LPG) vehicles between Thanksgiving and Christmas.

LPG will be available only on the 14,200 GVW cutaway with 159" wheelbase. These vehicles will be capable of being converted to school buses, ambulances, and shuttle buses. Knapheide Manufacturing, a Tier One supplier for GM, will complete the fuel-delivery and fuel-storage installation for two different LPG systems. CleanFUEL USA and Bi-Phase Technologies will supply the “under-hood” LPG fuel system — CleanFuel for the three-tank design (35 gallons, the equivalent of 31 gas gallons), Bi-Phase for the four-tank design (57 gallons, the equivalent of 50 gas gallons).

He said the three-tank configuration will be certified for school-bus applications, while the four-tank will not.

All are manifolded, all-steel tanks — 10 years for corrosion and durability — manufactured by Sleegers in Canada.

All underbody tanks are protected with substantial shielding for road debris, curbing, and exhaust and external heat sources.

Horsepower (324) and torque (373) are identical to the gasoline 6.0L engine. The net weight increase for the three-tank system is 345 pounds, and 500 for the four-tank system, reducing the standard payload from 9122 pounds to 8777 (three-tank system) and 8622 (four-tank system).

Langhauser said the 2013 cutaway lineup will include a 139" wheelbase on the 10,050 GVW. It will include the current 9R5 option (multi-leaf spring pack). The gas version will be released as an SEO, the diesel as RPO. The rear GWAR remains 6084 pounds.

The 177" wheelbase on the 13,980 and 14,200 will include the current upgraded hardware from the 159", 14,200-pound model, along with additional frame reinforcements. The front GAWR remains 4600 pounds and the rear 9600.

Langhauser also said E85 will be optional on all cutaways with the L96 6.0L engine (FHS).

More than 2600 LPG stations are now in operation, Langhauser said.

Technical bulletins

Renee Bryant, engineering group manager of upfitter integration, gave an update on upfit advice contained in recent GM technical bulletins.

She said technical bulletin #94 contains best-practice guidelines for installing body mounts on the Chevrolet Express and GMC Savana Cutaways for 2008-2012.

The mount package body upgrade is P/N 15030648, which consists of a mount assembly, nuts, bolts, and washers. This mount package can be obtained through any GMC dealership.

Coming soon is bulletin #98, which will provide service body mounting guidelines for light- and heavy-duty Chevrolet Silverado and GMC Sierra pickups with P/U box delete (ZW9) or P/U box removal.

Also coming soon are body builder manuals: 2012 electrical for Silverado/Sierra/Yukon/Tahoe/Suburban and Express/Savana. Information for LPG vehicles became available at the start of regular production in the fourth quarter.

CNG pickup

GM plans to expand its offerings with a CNG bi-fuel commercial pickup truck that will be available early in the fourth quarter of 2012 and will help satisfy a broader range of needs for commercial customers looking for a one-stop alternative fuel vehicle from the factory.

The bi-fuel commercial trucks will be covered by GM's three-year, 36,000-mile new vehicle limited warranty and five-year, 100,000-mile limited powertrain warranty and vehicle emissions warranty, meeting all EPA and CARB emission certification requirements.

IMPCO Automotive will also integrate the CNG bi-fuel delivery and storage system into the pickups.