Though the X6 hybrid was revealed as a concept vehicle a while back we recently have not seen or heard much more about it. Until now! Chaz, one of our readers happen to snap some photos of a few different prototypes and graciously provided us with them. In the photos you can see one large chop shop mutant version of the front hood bulge and the other with a more production ready hood.

He was also able to snap a photo of the MB M class with a similar system, notice the HEV tag on the side is that internal code or a new label for Hybrid?

These models could utilize a two-mode hybrid system, much like the current GM offerings (Tahoe) on the roads decked out with large HYBRID lettering on all sides so that everyone knows your SUV is a hybrid.

The two-mode hybrid system is the product of a joint development program between GM, Daimler, Chrysler, and BMW that began a few years ago. The technology originally was designed for public transportation in city buses utilizing a two-mode hybrid transmission produced by Allison.

The two-mode name is due to the two possible operating modes one for city and one for highway. At low speed (and low load),the system can work off the electric motors and batteries, use only the engine, or a combination of the two. At high speed or with a load the system switches to the second mode and runs on the gas engine with the electric motors available if needed for added power.

The two-mode system uses a pair of electric motors within an electrically-controlled, continuously variable transmission (ECVT). There is no perception of switching between modes, and the system is contained within the confines of a transmission unlike offerings from other manufacturers (single mode, Toyota/Honda). The A/C, power steering and other like systems will be electric powered and there will be regenerative braking to help charge the batteries.

There will be an advanced energy management system that will control the use of the gas engine and the electric motors. We have heard that BMW will not be using cylinder-deactivation, though it is still a possibility. If so, some of the cylinders of the gas engine may be shut off during certain conditions to conserve fuel while allowing the electric motors to pick up the slack.

The specifics of the BMW system are not yet known, though it makes sense that they would offer a hybrid version of the V8 gas guzzler first. Since these systems were jointly developed expect each to be very similar in nature; BMW is said to have taken a more performance route with their version, though we are not sure what that means considering the added weight and lack of direct feedback the system allows.

What we do know is that the system should increase MPG by between 20-30% in the city, whether or not the additional price tag is worth the savings is a whole different debate. The technology has already won Green Car of the Year in the Tahoe so the system does indeed work as advertised.

In a nut shell BMW had to hop on the Hybrid bandwagon for image reasons and to meet upcoming emissions requirements. BMW has in the past said the added systems would diminish overall performance and not be worth the fuel savings. BMW has instead been a proponent of diesel as a bridge to hydrogen power. BMW has been able to obtain more MPG out of diesel (with low emissions) than many hybrids obtain. The future “F ” 7 series will also feature a hybrid option, so this is not the end of the hybrid models from BMW. We doubt the 3 will ever see a hybrid as the performance would greatly suffer and with a diesel the MPG would be extremely close to a hybrid so what is the point?