Engine oil Mobil or Castrol

I'm seeing a lot of strife around these comment parts on this post; but I will tell you this: If previous owner used only conventional, you best use conventional for the sake of the rubber seals on the block. If you want to eventually run synthetic after your first rebuild, be my guest, although I would recommend going the sohn adapter at that point, just for extra insurance that what you're doing is good for the engine.

I don't know where you're located, but I've personally ran Castrol GTX oil in all my cars up until now; the only thing is, it's harder and harder to find conventional oil that is of thinner grades. Which isn't a bad thing, because the RX8 needs thicker oil than what's on the oil cap anyway! 5w-30 should be your minimum thickness, but really, it's recommended you go thicker, to like 10w-40 for year-round, and 20w-50 for track days or extremely hot climates. There's this shell oil for diesel that's rated at 15w-40 that I was going to potentially pick up and start using. Yeah your fuel economy is gonna drop a tad, but you're really doing it for the sake of your bearings.

P.S. get an oil catch can that vents to atmosphere if legal in your area. It will save you heaps of headaches down the road ????

I've been having my Hybrid oil changes done around 12k ODO miles (~6k ICE miles). Mobil 1 Hybrid full synthetic oil. Blackstone says very little oil contamination at all and additives all still in great shape. In comments, they say I can go longer.

Castrol magnetic 5w30 best utk jimat petrol

I switched to Castrol Edge 5w40, and what a difference! It loves it. We didn’t lose any fuel mileage, just as Pepe. but much much smoother.

Car idles smoother with Castrol it seems.

I run 10w-40 castrol gtx been running it for the past 5 years I drive a 2011 wrx

ran Castrol 20w50 GTX in my 2.4 Naps Z D21 since new the mechanic who put on new head gasket w/215.000 due to a bad radiator said engine looked brand new inside

Used 5w40 castrol for most its life, but vw504 standard is good too. Using it now and the old man says it runs good.

It depends on what ur using the car for. I’ve used super tech, Mobil 1, and pennzoil and haven’t found a single difference in feeling, temperatures, or oil consumption.

HP Prolube is a very low quality oil compared to other oil brands in the market. Castrol has good head sound dampening, as does Rowe, both great for gear shifts and clutch feel.