Originally Posted by mkoesel
In my estimation, primarily the employment of BMW's Valvetronic technology.
The S55 engine will feel similar to an N55 in all the same ways that an S65 feels similar to an N62. In other words, the similarities will be few to none. Remember, torque is great for towing and butt-o-meter sensations, power and weight alone (or nearly alone) drive performance.
Also, not to disappoint, but the F8x will almost surely not be significantly lighter than an E9x 335i.
Thanks for the response. Looking forward to test driving when available.