CSF’s pursuit of cooling perfection continues with improvements to The Ultimate BMW B58 High-Performance Heat Exchanger. As of October 2019, CSF has released a new and improved “Version 2.0” of the BMW B58 Heat Exchanger.  Improvements include the following Three (3) key updates:
Upgraded inlet/outlet design with new tapered entry and exit points from end tanks, resulting in optimized water flow and increased performance (matches OEM spec).*
After extensive wind-tunnel, dynamometer (rolling-road test), and field testing, CSF engineers have improved the core spec from Version 1’s 68mm 2-row core with 8mm fin height to Version 2’s Ultra-efficient 42mm 2-row core, with CSF’s B-tube technology, and 6.5mm multi-louvered fin height. *
Increase of 15% more cooling tubes used in the core vs. V1 design for better surface area contact and heat dissipation.
Results in optimized airflow through the heat exchanger core and into other cooling system components for maximum performance of the entire cooling system. (Especially critical if installed in an X-Drive model with transmission oil cooler placed in front of heat exchanger)
CSF V2 design: 2-row 42mm core vs. OEM design: 1-row 26mm core. ~62% increase in core fluid capacity
Now includes hardware mounting kit* for applications that have a factory transmission oil cooler mounted in front of the heat exchanger (X-Drive models) 
(OEM #17118625431).