Excuse my ignorance but I had no idea what valvetronics were. The salesman said it was on the 7 and on the 545 that I was test driving and I thought it felt like an awesome engine. I didn't find much when I searched previous threads, so I thought I would share this helpful article that helped me understand what it is. After all, soon 2/3 of E60s will have valvetronic engines.

Check out this explaination: http://www.bmwworld.com/technology/valvetronic.htm

 

I believe it is the engines with the lifts on the valves are electronically controlled for better timing. Valves and electronic controls = valvetronic engine. I don't have much more than that off the top of my head, but I believe that is the jist of it.

If you do a search here for engines, I believe the 2006 engine topic will come up and it contains some valvetronic information.

 

Depending on the speed, accelerations, etc., the valve timing (opening/closing) is adjusted so that more/less fuel is burned. More efficient and will give better acceleration, torque etc.

 

This exact question is covered in the FAQ which you can see by clicking here.