I fly a Piper PA-28-181 and noticed lately in the extreme cold -10c and colder that the oil temperature is only just making it to the green. This is a steam gauge so I can’t give you exact temperatures. Someone suggested to me that there’s an item that can be installed where it will trap the heat that the engine generates in order to keep the oil tank even warmer. If anyone is familiar with this item and can make me a recommendation, it would be greatly appreciated. This would put my mind at ease Bonus points if you can answer this question out of curiosity since I’m on the topic of oil - should I expect more or less fuel consumption when the oil is colder? What about when it is warmer? Thanks!