Got a 1983 Chevy pickup with the 350 motor that I use as an "around the farm" kicker. Motor was completely rebuilt 1,500 miles ago but I only put a few hundred miles on this truck a year. Was using Pennzoil 10w-30 but switched to Mobil l 10w-30 for my last 2 oil changes. I change oil and filter every Spring which averages out to around 450 miles each oil change. This Winter was unusually cold and damp here in West Tn. I did a lot of cold starts and driving only 3 or 4 miles before I shut it down and let it set for a day or two before I restarted it. Did my annual oil change yesterday and was surprised to see the oil that I drained out was gray and milky colored. Had never done this before but as I said this Winter was colder than normal. My coolant level is fine and no excessive water vapor is coming out the exhaust so I don't think it's a head gasket problem. Is there a motor oil that I can use that is better about not sludging for these short, not long enough to warm up, trips? I know this type driving isn't good for any vehicle but that's just the way it is for this truck. Thanks, and I hope this msg. wasn't too long as this is my first post to this site as I just became a member today.