I drove about 300 miles this evening from Madison, WI to Saint Paul, MN. All interstate miles, normal driving. As I neared my house in the city, I switched to manual shifting to engine break for a stop light. It's cold here. About 2 degrees Fahrenheit. The engine temp was about 170, so out of curiosity, I wanted to see if I could raise the engine temp by staying in a low gear from one stop light to another. I stayed in 2nd gear and revved no higher than 4000 rpm for about 30 seconds. Sure enough, the temp went up a tiny bit, but I detected what seemed like a burnt rubber smell. I wasn't worried, I thought it was someone else. I got home and still detected a smell, so I opened the hood to find a light splattering of oil on both sides of the engine. I assume it is engine oil, but I'm not 100% sure. I restarted the car and let it idle. No warning lights or spewing liquid from the engine compartment. Any ideas what happened?