It says Z4M across the top. What may be confusing you is that one line on the graph is horsepower and other one is torque. This is not a comparison of two different cars.
Originally Posted by JohnnB
By the way, I found this somewhere when I was looking at cars if you are interested. I am pretty sure it is M vs Si. Can someone confirm that those are the Si numbers?
2009 335i e92
2013 Porsche Boxster S
2006 BMW Z4 3.0si- Gone, but not forgotten