What oil weight do you use?

[metro123]

hello,
I just recently bought a 99 m3 last saturday plan on doing an oil change in a day or two. ( i like synthetic much more then conventional oil). i have some 5w-30 castrol european formula in my garage. i read the factory weight is 10w-40. is it okay to go to 5w-30? or should i stay with 10w-40. i live in seattle, so average temperature is ~60 f. and maybe 80 during summer on good days.

[nondescript]

This really has been covered a lot... There is some funky voodoo black magic garbage that most e36 M3 owners hold to here in the states... Let me try to simplify this for you:

If your car came with dino-juice - stick with dino-juice... In 1999 it was a 15w40 mineral based oil - I'll do a little research as to the options for you if you confirm that this is what you need... Or if you really want to switch to a synthetic; go with AMSOIL 10w-40... It is thicker than most other synthetic oils of the same rating - and as such it is more compatible with cars used to the thicker natural oil.

If your car came with synthetic - in 1999 that would have been a 5w40 synth that BMW NA doesn't recommend any more... There was a service bulletin that changed this to the 5w30 castrol bmw oil... Go with this. it's a great oil for cars that have lived with synth oil all their life.

I last talked about this topic in this thread:

1995 M3 ticking valve?

And the SIB is #110400...

And the oil in question is the 5W-30 Synthetic: P/N 07.51.0.017.866

...

There was a switch in e36 M3's sent to the US sometime during 1998 build dates from the dino juice to the synthetic I mentioned above. Give your build date and your VIN to the dealer and they can tell you which oil your car shipped with originally...

[bizlur]

I use Castrol Synthec 5w-30

[Evo Lud]

I have been using Mobil 1 5w-30 fully synthetic year around, I live in Colorado where the temp. goes from 0-90 F'. ????

[streetcuda]

I live in Idaho so with temps running from -15 in the winter to 100+ in the summer. In the winter I usually ran Castrol 5w30. When summer rolled around I'd switch to a 10w40 or 15w40. In a fairly temperate climate like Seattle I don't see either having a problem. You're fine to go with 5w30

[saint166]

i use the euro 5w 40 amsoil . since i never winter drive my car i also only change it once a yr

[streetcuda]

I ran Lubro Moly Voll-Synthese 5w-40 my last oil change before I sold it to my buddy. He changed it a few weeks after that. It had been in the car for about 8 months and 5k miles. Still looked pretty good when it drained out but the stuff is expensive! You can go for longer oil change intervals and it's a level 4 synthetic(the stuff in the states is level 3), but probably not worth it unless you need something that stands up a long time and offers superior protection. I usually change my oil every 3-5k anyway so it's hard to justify spending the extra $ if I'm not going to use it through it's full lifespan.

[Insane]

On my 97 m3 3.2l I use Castrol TWS racing oil, 10w-60

[UberMeister]

i use motul 300v 5w40