DeviantArt and I fight. I don't use it anymore. >_o
In case you still need help with that lab report, I THINK I know what it's tralking about. Just don't take my word 100% on it. You'd want the less viscous one in the summer, because if it runs smoother, there will be less friction, producing less heat, making your car less likely to overheat. You want the more viscous one in the winter because it produces more friction, ergo more heat, keeping your engine warm and running in the cold.