Originally Posted by Savannah Buzz

Dexcool if changed frequently in a perfect world may be OK. Allowed for extended stay not so good. Topped off with who knows what even worse. Turns into sludge. Restricts flow of water, like having half a radiator. Motors run hotter. Mechanics can afford new boat payments. Engine design is late 1950's, when oil change interval was 1000 - 3000 miles. Taking that same dirty engine and putting expensive oil in it and running to 25,000 between drain and filter changes not such a good idea. You can run anything you like, but don't go low viscosity when hot (40 or 50 as last number); and change oil every 5000.

Otherwise, Cedric Whistlebritches, infamous Rover wrench wrangler, is waiting for you.