2009 Volvo S80 I6Enlarge Photo
The diesel hybrids will first appear in Volvo's larger sedans, crossovers, and SUVs. The system consists of a front-mounted, front-wheel-drive diesel powertrain and a rear-mounted, rear-wheel-drive electric propulsion system. It has electric-only capability at low speeds. Magnus Jonsson, Volvo's senior vice president of R&D, said that plug-in hybrid models will come "very quickly" after the first hybrid models become available.
Because both diesels and electric motors produce the bulk of their torque at low engine speeds, the combination of the two hasn't been a popular one where fossil fuel/electric hybrids are concerned. But, conceivably, proper gearing will help keep the diesel's RPM low enough while cruising to boost efficiency. This seems like an ideal setting for a CVT, where ratios can be adjusted infinitely.
Lex Kerssemakers, Volvo senior vice president for business and product strategy, said the firm is contemplating abandoning the V-8 engine that it recently installed under the hood of its S80 and XC90 vehicles. It will likely go back to turbocharged sixes if it nixes the V-8. Said Kerssemakers: "if the environment is changing, you can be stubborn, or you can look for alternatives."--Colin Mathews