Just did an oil change this weekend so my next one will be in December, which means it will be colder weather. I use 10w30 now. Would going to a heavier weight be better for the car for the winter months, like 10w40 the next time I change the oil? The car sits outside and not in a garage, so there will be alot of really cold winter mornings. I always let it warm up for 4 or 5 minutes before driving too.

 

No. Lighter weight in the winter, heavier in the summer.

 

^ that's what I was thinking. ^
Heavier in the summer because it's hotter and will thin out easier.

I'm going to be running 5w20 full synth Mobil 1 all year cool.gif

 

For DC winters, I'd recommend 0W-30.