Read an article in the new Car and Driver on the importance of coolant especially in racing/ HD applications. They said Xerex came out with a GO-5 coolant that DC has been using since 2000 which is rated for 100k miles in the gassers- they talked about the commercial Extreme Duty Coolant favored by many diesel truckers and fleets- apparenty goes right in without mix and is good for 300k- apparently very expensive but worth it if it is that good- anybody using this? I will be changing coolant by the end of the year and have been researching the best- money is not an object since it is for Big Green.