Originally Posted by
Nails
I would suggest figuring out what weight oil your car likes best then switch it to synthetic once you got the viscosity figured out. 5-30 is pretty broad and you should be ok with it but if 5-20 works then you don't need that extra thickness. 0w is the thinnest oil obviously and would provide the least protection on a cold engine which, ironically, is where the most wear usually occurs, at start up before oil is distributed. But in sub freezing climates a thinner oil makes less resistance for cold cranking start-ups.