The Dinan B4x/B58 heat exchanger for the F2x/F3x chassis assists in mitigating these issues with a more robust core (48mm thick Dinan core vs. 27mm thick OEM core) that wields 78% more heat transfer surface area for improved cooling capacity. The significant increase in core thickness requires unique "L" shaped end tanks to be incorporated as well, which also contributes to the overall thermal mass (ability to absorb, store, and release heat) improvement beyond the OEM setup. With up to a 15° IAT delta recorded over stock the Dinan heat exchanger is ready, and able, to assist in extending your vehicles ability to deliver maximum performance time and time again for your driving enjoyment!