I did some searching for "winter oil" and "cold oil" here on TT and I didn't get a lot of specific information back, so I figured I would ask here. I'm going to be riding in 20F-25F weather for the winter (hard use, lots of full throttle pulling with the Mountain Horse) and wondered what a recommended oil weight would be. Currently I'm running Yamalube Semi-Synthetic 10W-50. The bike will be seeing LOTS of hours this winter so I would like to buy oil at more than a quart or two at a time. My plan is to change the oil every 10 hours without exception and change the oil filter every other ride. Suggestions? Also, can I get away with changing the filter every other ride or should I change that every ride as well? Any good place to buy 10 filters at a time and bulk oil would be great. My dealer is killing me over these prices.