27 degrees when I left work at 4:30. Forecast is a low of 15. At startup today, I heard a few pops from the rear when I got in. Few more backing up and a thud (pass front) when I turned backing out of parking space. Once I got moving it was ok and drove fine home. I changed oil Sunday. Good thing, I think. I was getting a few second of clatter when starting with the 20W50. Switched to 10W30. Using Valvoline racing oil and Lucas zinc additive. Thinking pops might have been brakes. We had light freezing rain this morning.