new six-speed Hydra-Matic 6L80 RWD electronically controlled automatic transmission backs the 6.2L engine. The six-speed automatic has a wide, 6.04:1 overall ratio – including two overdrive gears – that helps deliver an excellent balance of performance and fuel economy. Also, the 6L80 has a "tap up/tap down" capability that allows the driver to manually select upshifts and downshifts with a button on the column shifter. The new powertrain combination helps the 2008 H2 and H2 SUT deliver an additional 1,500 pounds (680 kg) in towing capacity – an increase from 6,500 pounds (2,948 kg) to 8,000 pounds (3,629 kg). A host of additional powertrain revisions also contributes to the H2's improved performance and efficiency, including:- Larger-capacity cooling system complements larger, more powerful engine
- Electric engine cooling fans reduce "drag" on engine, enabling more horsepower
- Regulated voltage control maximizes fuel economy by charging electrical components only when necessary
- New LAN electrical architecture is more efficient and uses less electrical energy
- Standard 3.73 rear axle ratio
This does talk about the tap up/ tap down feature for the "M" on teh shifter.
But WTF is with the 3.73 rear axle?
http://www.gmhummer.com/timeline/2008/2008hummerh2.htm
EDIT: LINKY