http://www.motorauthority.com/bmw-co...ve-hybrid.html

[quote]. . .
Conventional hybrid systems allow efficient motoring only in relatively small or medium-sized vehicles at relatively low speeds. This is because most of the power coming from the combustion engine has to be conveyed most of the time via the electrical path of the transmission and because of the use of a high level of electric power. A car with enhanced dynamics, performance and running speeds would therefore require a larger combustion engine calling for less efficient, larger and heavier electric motors.
. . . [quote]
First some facts and data about the current Prius transaxle:

• 28% takes the electrical path
• 95%*95% = 90% energy efficiency generator-to-motor
• 28%*10% = 2.8% energy lost over electrical path

To put this in perspective, this is functionally equal to the energy loss of one additional gear stage.
This description is inaccurate as MG1 power flows directly to or from MG2. However, it is an accurate of what the Volt, a series hybrid, will do. But the Volt carries a substantial amount of power in the battery.

As long as BMW continues to believe this is the case, they will be disappointed by real world test results. In fact, it only takes a simple scan of existing HSD hybrids to understand how badly BMW has failed to understand the technology:

• 289 hp - gas engine
• 221 hp - motor power
• 5,220 lbs - curb weight

So <ssssuuussshhhhhh> we don't want BMW to wake up and realize they may have published a false analysis of the Toyota HSD system.

Bob Wilson