2005 GMC Graphyte review

GMC Graphyte review:

The GMC Graphyte concept vehicle is a refined SUV with all the capability expected in a four-wheel-drive truck, but with 25 percent improved fuel economy enabled by GM's latest two-model full hybrid propulsion system. A tailored design, including an elegant, metal-framed grille gives the Graphyte an urban flair. It was designed and built at the GM Advanced Studio in Coventry , England .

The midsize Graphyte uses a two-mode full hybrid combined with a Vortec 5300 V-8 with Displacement on Demand (DoD) technology. It is similar to the hybrid system that will be available on GMC Yukon and Chevy Tahoe full-size SUVs in 2007.

Two-mode full hybrid technology is at the center of GM's three-prong advanced propulsion strategy that aims to take automobiles out of the energy and environmental debate. Its universal design allows engineers to scale the architecture to fit vehicles of any size. The system fits within the space of a conventional automatic transmission, with a battery pack providing the electric power.

''GM feels it is best to employ hybrid technology first on large vehicles, such as buses and SUVs, because they generally are the largest consumers of fuel,'' said Stephens. ''With the Graphyte, we've demonstrated its integration into a type of vehicle where its fuel-saving technology will do the most good, while maintaining all the utility for which GMC trucks and SUVs are known.''

Packaging for the two-mode full hybrid drive system and supporting components in the Graphyte includes a 300-volt NiMH cross-vehicle battery pack located beneath the rear passenger seat and accessory systems under the hood to support the electrically driven HVAC, power steering and power brake systems. The drive system itself, including two compact electric motors and a series of gears that provide an infinite range of drive ratios, is contained within the case of a conventional Hydra-Matic 4L60-E automatic transmission. End of GMC Graphyte review.