What oil and octane fuel do you use?

[Farm_E30]

15w-50 mobil 1 synthetic with a bosch oil filter
87 octane normally, 92 sometimes.

[Nick_S]

Castrol gtx high mileage 10w-40 when its warm, 5w-30 in the winter. 93 octane, usually from Marathon stations. I've got a TMS chip for the M42.

For giggles last fill up I tried 89 and really can't tell a difference. I got used to only using premium because my SVT Focus I had for 7 years had to use it so I really don't mind the extra money. I figure it's barely $2 more a fill up, $8 a month more? Why not.

[85e325]

mobil 1 15w50
good 'ol 87 octane

[DatUtahGuy]

I forgot what oil, lolz

and 93 oct

[Def30]

Thank you all for your feedback and participation in this thread. I was due for an oil change, and wanted to see what people used. So I went out today and bought 20-50 Valvoline VR1 oil and a Premium Bosch Filter.

I am gonna tell you that I felt a noticeable difference between my previous 10-30 and current 20-50. The thickness makes the motor run much much smoother

[M3Philipp]

I'm using 5w40 Liquiy Moly for my 318is M42B18.

[rogue38]

Castrol 20W-50
(Thought about experimenting with other weight and brands, but here in middle GA summers are too hot to go with lighter oils and winters vary drasically).

I run premium 93 from a Pure station that is ethanol free (they only have 87 or 93).

All my cars get at 3 mpg better on the 100% gas than on ethanol laced crap. Been hesitant to run 87 as my experiece with my past e21 and 87 equalled a lot pinging.

[nando]

15w-50 mobil 1
Conoco 92 (ethanol free - for now)

Not stock - on an M20, you definitely don't gain anything from higher octane unless built/tuned for it. M42s are built for 91 minimum. it won't kill it to run it on 89 but beware you don't have knock sensors.

the wife's car gained almost 3mpg switching from E10 piss to Conoco. The local shell/chevron used to be great, but then they built a huge ethanol plant and turned it to shit. Conoco is the only one I know of around here that doesn't have E10.

[SlamedIAm]

20w50 and 93 octane (Turner chip)

[MikeDE]

In the M42, I run: 10w-30 Castrol GTX in the 'wintertire' months, 15w-40 Castrol GTX in the 'summertire' months. I change it around the time I change my tires for the season, depending on avg temps.

The only 5w-xx available here is either Part or Full Synthetic IIRC, €€€!!!

I tried Liqui-Moly, but seemed too thick in the cold. I got some pretty loud cold-start ticking.

I usually go to AGIP for fuel. Super costs the same as SuperPlus, so I pump the Plus, 95ron.

[latinobimmer]

if you have a m42 or an m50 you want to use that vr1 stuff, or rotella diesel oil, with zinc additives.

Those are the engines that fall apart with modern oil.

My M50TU with 222k miles on none of those oils disagrees with what you say.

[iwantspeed]

20w50 castrol
91 octane chevron
Jim comforti chip

[Massimo]

mobil 1 0w-40

98 octane