the plot thickens..literally

i made the mistake of using mobil 1 ( which ive always been using since my first oil change on my new motor) 15w50 during winter . i didnt realize it when i was putting motor in but now the temps are down in the teens and at startup my autometer gauge is telling me a startup of 20 psi or whatever but after like 5-10 secs it goes to 30 and after like 30 seconds im up to 50. now my question is, my motor is brand new i dont want to harm it and i want it to last long time. is that 15w-50 doing more harm then good? it says it pours at -50 or some crap like that. what do u guys think.

Do you need to run that thicker oil to run? If you can stand it with what was working, then I would stay with it. Maybe there was something wrong or just about to break before you changed over to the thicker oil, but it just topped off when you changed it.

i never switched over to thicker oil in the winter... always have and still use synthetic 5w30...

You should be using 5w30 in winter and 10w30 in summer.
5w in the winter because its lighter and makes startup easier.

well i switched like 7 months ago and the motor ran with the oil for like 2 months until i blew tranny and sat for about 5 months until now until which i wasnt thinking and threw it in b4 startup. the motor is brand spankin new i switched to keep my motor from wear. will 15w-50 hurt my motor during the winter cuz i am using it everyday??