e30 M20 Oil Change

[SkiFree]

https://adamsautosport.com/bmw-m10-m20-m30-engine-oil-guide/

This is a good list of what oil to run in your E30. What you can get kind of varies by locality.

[ACVC325ix]

valvoline vr1 20w50

+1

[Peertwelve]

Rotella T4 15w40 or Valvoline VR1 20w50. These engines need thick oil with high zinc content. If you use oil for modern engines, you won't get that - they're specifically low-zinc, because zinc wears out the catalytic converter.

I’m battling a melted catalytic converter issue. Wideband o2 sensor is in the mail. Just found this response while wondering if my issue is related to using the VR 1 20w50.. could the zinc level of this oil melt two aftermarket flow master cat, each within 500 street miles, zero track miles? Tia!

[digger]

No , melted cat is a tune issue often too rich which causes lots of heat from burning fuel in exhaust

still you should not be using 20w-50 we aren’t in 1980 anymore. There is no reason to use an oil that thick as there is nothing in the engine that needs it.

[bangn]

500 miles, wow! excess unburnt fuel kills cats, how's your fuel/gas consumption? running condition? Plug condition on each pot? engine have a misfire?

[packratbimmer]

I have seen Castrol GTX classic https://www.castrol.com/en_us/united...x-classic.html which I assume has zddp and also a bottle without the word "classic.'' I am a big longtime fan of Castrol, but would be cautious about straight GTX conventional products - they may not have enough zinc/phosphorous/zddp - magic stuff.

[packratbimmer]

I have been using Valvoline 15W-40 diesel oil from Tractor Supply https://www.tractorsupply.com/tsc/pr...gine-oil-1-gal for a while and just hope there is not too much zinc/phosphorous/zddp - magic stuff in it. My car burns pretty much zero oil so I'm not too worried about excess additives affecting the cat. So far excellent changing at 3K.

[hasa]

I've raced 10 years with 15W-40 big diesel oil, called Mobil Delvac MX. Reason for this is just trying to get zddp stuff supporting the old valvetrain design.

[packratbimmer]

If you are new to flat tappet engines, please learn the easy way from your friends here on the forum. Read. Use oil that will protect your valve train! I learned the hard way and have a couple of gnarly cams to prove it. zddp, just enough to protect, but not foul the cat, is what one needs.

[jeffnhiscars]

Spec is 20-50 and M1 15-50 (close enough for me) has about as much zddp as anything out there....and it's $23/jug from WM

[varg]

Mobil1 15W50 does seem to be a really popular choice, I use that these days. With the turbo and the florida heat using the synthetic 15W50 helps keep my hot oil pressure up, the conventional drops off measurably as the oil ages. Don't know if that's just my old worn out boosted engine or normal M20 affair but upon installation of my oil pressure gauge years ago I noticed that my hot pressure at idle was marginal with Rotella 15W40 after a couple thousand miles, 7-8psi at idle, and I've always idled at 850rpm+. With M1 15W50 I don't really see under 10psi unless the engine gets really hot sitting in traffic during the summer. Oil analysis shows that 3,500mi or show is about the limit for keeping the oil properties within spec with my particular car. An M20 in better condition with no turbo will probably go much further without oil degradation.

[digger]

Mobil1 15W50 does seem to be a really popular choice, I use that these days. With the turbo and the florida heat using the synthetic 15W50 helps keep my hot oil pressure up, the conventional drops off measurably as the oil ages. Don't know if that's just my old worn out boosted engine or normal M20 affair but upon installation of my oil pressure gauge years ago I noticed that my hot pressure at idle was marginal with Rotella 15W40 after a couple thousand miles, 7-8psi at idle, and I've always idled at 850rpm+. With M1 15W50 I don't really see under 10psi unless the engine gets really hot sitting in traffic during the summer. Oil analysis shows that 3,500mi or show is about the limit for keeping the oil properties within spec with my particular car. An M20 in better condition with no turbo will probably go much further without oil degradation.

i use 10W-40 in winter and 15w-50 in summer (or at least that's the plan generally) often i have also used 10W-40 in summer for periods if i haven't gotten around to changing it and yes the hot pressure does get sub 10 but it actually doesn't matter as its just relative and indicating the that oil is thinner not that you arent getting flow