> kind to help. I used to using the Castrol 5w-50 engine oil for my 5kcst.
> Last week, I changed the engine oil to the Mobil 5w-30, after a 30 miles
> trip the oil pressure lite came on when the car restart. The weather now
> here in Bloomington, Indiana is around 25F to 45F and still no snow yet.
> Also, after I read the viscosity chart in owner's menu and I found that
> the 5w-30 engine oil's temperature range is only form -20F to 20F.
> Am I using the wrong viscosity grade of engine oil?
The recommendations in mfr's manuals are probably based on the usage of
dino oil. Since most dino oil has narrower range of usability, you should
be worried if you're using dino oil.
If you're using synth oil, however, then check for other things. Is the
oil level okay? Is the oil pump/delivery working? Does the new oil filter
got drain-back check valve? I wouldn't worry much about synth oil as long
as the mfr's manual recommends the thickness somewhere in the manual.