I'm in upstate NY for school and my poor car is sitting outside in the freezing cold. I changed the oil right before I left North Carolina to come up north. Since I've had the car at 22,000 miles (150,000 now) it's had 10w-30 Amsoil synthetic, but I was out of Amsoil, so I went with 5w-50 Castrol synthetic. I hardly drive the car more than 10 miles at once here so I thought that would be a good choice until my next oil change at least.

Last week sometime I started the car and the oil pressure light was on. The temp was about -4F so I thought, it's probably just really cold. 10 seconds later, the light shut off and didn't come back on so all was good. It now does this every time I start the car after it's been sitting for over 8 hours. Of course I checked the oil level and it was at an ok level.

Do you think this has anything to do with the oil type change, or something else completely? I don't know if it's related to the time that the car sits, or the cold temperature because I don't have a garage to park it in overnight.

Thanks for the input!

--hoyt