I replaced the entire pcv system last year as it was way overdue & causing an erratic idle. I read in the manual that volvo specs Castrol 5w-30. Does anyone know if it matters to run regular oil, synthetic, or a blend? I need to replace it soon & am looking for some feedback.

 

Mobil 1 5w30 or 0w40. I run 0w40 in my Saab my mom runs 5w30 in her Volvo both full syn.
Blends are scams

 

I've read good things about Castrol Edge 5w-30. I'm gonna go that route.

 

all castrol mobil and pennzoil are about the same. regular oil is just fine for a non turbo engine. careful with synthetic oil, it reflows sludge and the filter can get filled sooner.

 

Well, for the cost and potential non-issue with a non-turbo, maybe I'll stick with the cheap conventional oil.

 

Well if you have a high mileage or older car you want to use full synthetic. If you dont have a turbo you have a choice but I find synthetic is just better overall it lasts longer gives you better preformance