Recently bought an E46 with a M54B25 engine with 350k kilometers (over 200k miles) on it, car runs great for it's age and I wanna take good care of it. The recommended oil is castrol 5w30 I think but I'm a Valvoline fanboy plus it's much cheaper here.
I live in southeastern Europe where summers are really hot and winters are really cold so from what I figured neither 5w30 nor 40 are good for the entire year?
What Valvoline or Shell oil can I put into this thing without needing to worry?
Yes I know it's gonna burn it up anyway, I'll carry a bottle in the trunk for refills.
The car's got LPG installed if that makes any difference

Blast it with piss.

>>28498238 (OP)

5W is fine until some truly preposterously cold weather where you wouldn't want to start the car without a block heater anyway and the hot end viscosity only matters on a warm engine. Just grab a jug of whatever decent quality BMW LL-04, I used Castrol Magnatec 5W40 in my old M54 chariot and even -20°C didn't phase it.

>>28498244
I was definitely only gonna go with 5W, 5w40 is supposedly better in this case because of the high mileage but that weight was my concern for winters since 30 is by default.
I'm not sure if any of the oils sold in my area have the LL-01 or any other bmw tag, all I know is that I need 100% synthetic

>>28498238 (OP)
I switched to 5W40 in mine and it runs better, used to get the flickering oil pressure light at idle when it's hot outside but it's gone now.