The first brilliant days of autumn found competitors in the world's premier clean-energy vehicle event — Challenge Bibendum — competing for environmental honors amidst the natural beauty of California's Sonoma Valley before driving their message of “sustained mobility” over the Golden Gate Bridge onto the streets of San Francisco.

The Challenge, created and sponsored by Michelin, opened competition to commercial vehicles for the first time this year, with 12 entrants covering Class 3-8, drawn both from OEMs and fleets. On hand were vehicle entries or exhibits from Allison, Cummins Westport, Isuzu Truck/Westport, Eaton, Freightliner and Volvo Truck North America. Along with Michelin, Bosch and ChevronTexaco served as the main sponsors.

Big winner from the trucking field was a joint entry by Isuzu Motors Limited of Japan and Westport Innovations of Canada.

The prototype medium-duty Isuzu ELF (sold here as the Isuzu and GM N-Series) powered by a direct-injection compressed natural gas (CNG) powered truck developed by Westport drove away with gold medals for fuel efficiency and emissions performance as well as a silver medal for vehicle noise.

Tadashi Ioka, Isuzu's manager of corporate communications, told FleetOwner that the truck is the world's first mono-fuel “diesel-cycle” CNG truck. He said the OEM is considering “commercial opportunities” for the truck in Japan, North America and elsewhere.

The delivery truck's 4.5-L direct injection engine is unique in that it employs Westport's “hot-surface assisted” CNG-DI technology, which the partners said delivers “significant” power, performance and emissions advantages and requires no use of diesel as a “pilot fuel.” In plain English, it starts up and runs entirely on CNG.

Also coming away with honors from trucking's ranks was Volvo's demonstrator vehicle, the VN780 “Tech Truck,” which achieved an “A” rating in its category during the idling test. That test measured the amount of energy consumed by competing heavy-duty trucks during a 12-hr. period, and converted it into the equivalent gallons of diesel fuel consumed per hour.