The OE thermal management system for the B4x/B58 G-chassis BMW and Toyota GR Supra offers an improved formula from prior generations. With a setup where engine coolant is also re-routed through the heat exchanger, the system effectively assists in overall engine cooling as well as charge cooling. However, like its predecessors, it has room for improvement as it can be overwhelmed when the system is taxed aggressively or as power levels are increased. Once overburdened, this results in the undesirable outcome of power being diminished. Avoidance of this unwelcome scenario can be attained though with a Dinan heat exchanger that improves the overall thermal management system so everything runs cooler and more efficiently while being budget friendly. The Dinan B4x/B58 heat exchanger for the BMW G2x/G4x and Toyota A9x Supra assists in improving overall charge cooling using a more robust core (45mm thick Dinan core vs. 26.75mm thick OEM core) that wields 68% more heat transfer surface area for improved cooling capacity. The significant increase in core thickness and full-size end tanks contribute to the overall thermal mass (ability to absorb, store, and release heat) improvement beyond the OEM setup. With up to a nearly 12º reduction in charge air temps 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! G20/G22/G23/G26/G29/G42/A90/A91