Full hybrids have to date been almost synonymous with Toyota's Hybrid Synergy Drive (HSD) system, which, in addition to being the technology behind all Toyota and Lexus hybrids, is licensed by Nissan for its Altima Hybrid and is used in a modified version by Ford in the Ford Escape and Mercury Mariner hybrids. This hybrid monopoly is about to change, however, as GM readies its 2-Mode hybrid system for introduction later this year in the Yukon Hybrid and Tahoe Hybrid SUVs. Like HSD, GM's 2-Mode system enables cars to run just on electricity, just on gasoline, or a combination of the two. The system makes use of a two electrically controlled variable transmission (ECVT) modes, which change based on the car's speed and engine demand. The result, according to GM, is a 40 percent improvement in city fuel economy over the gasoline-only Yukon, and a 25 percent improvement in overall gas mileage.
We took a ride along with GM this week in the 2008 Yukon Hybrid and got a firsthand impression of the next big thing in the hybrid world. Check out our photo gallery here.