CSF 06-10 BMW E60 M5 / E63 / E64 M6 Race-Spec Oil CoolerThe 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