Just change the oil when its good and hot. That'll get most of the crud out. I have switched all my vehicles over to synthetic at high mileage without issue. Go for it. Much easier winter starting. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K