CSF has received a lot of requests for an oil cooler upgrade for the E60 M5 and E6X M6. As the platform ages there are more cooling systems that need to be overhauled. This also presents a great opportunity to upgrade and keep your M5/M6 running better than ever. The CSF Design was inspired by the RPI SV1 design that was discontinued some time ago. This unit was highly regarded as the go to upgrade option for years and a must have for those who tracked or supercharged their M5/M6.The factory radiator for the E60 M5 and E6X M6 are pretty nice all aluminum units. While they have proven to be fairly robust, age and additional power tend to push them over the edge. Owners who have superchargers tend to have the most issues with their radiators. Between the extra heat produced with forced induction and the heat exchanger mounting in front of the radiator, the factory radiator is working overtime. The E6X models are also getting close to 20 years old and entering the "future classic" stage of life with many owners doing restorations and updates. Anyone who has restored/updated an older car knows the value of having upgraded parts that are as efficient as possible.The original OE oil cooler from BMW is an all metal design which would make you think it would be fairly robust. However, there are several weak spots in the design that tend to cause leaks. The CSF Race-Spec design reinforces the weak points, especially around the feed and return lines. CSF's solid line connection block can handle any abuse thrown at it while the reinforced and braced return tube is rock solid. CSF also upgraded the more fragile Tub/Fin core to a robust and durable Bar/Plate design. The core is 40% larger than the factory unit with 2 additional rows of oil cooling and much thicker core (63mm vs OE 45mm). This offers superior cooling capacity and volume for the oil system. TIG welded end tanks round out the slew of upgrades creating a much stronger connection than the factory brazed construction.Whether your M5/M6 is a casual cruiser or a track monster, everyone can benefit from an upgraded oil cooler. Supercharged S85's will benefit the most though as the added power comes at a cost of more heat. High oil temperatures can quickly send a car into limp mode and as well as lead to catastrophic engine damage. CSF new engine oil cooler is also a great preventative maintenance upgrade to avoid costly repairs and extend the longevity of your vehicle.CSF offers the best and most advanced Oil Coolers on the market. So when it comes to keeping your engine oil temps down as you push your BMW E60 M5 / E6X M6 hard on the street or track, a CSF Oil Cooler is the obvious choice.