What type of oil?

[mojo_monkey]

So i got my 1990 325iS and im loving it. I just have a few questions, what type of oil is reccomended for this car? I didnt get an owners manual with it and the guy said that he has been putting in 20w-50. Also, my fuel door seems to flap a little bit. Upon close inspection ive noticed that there is a little pin type of thing that looks like its supposed to slide out and hold a lip on the door and keep it from flapping. What engages this lip, is there a switch of some sort? Thanks for tolerating my newbie questions .

[yellow325ix]

When you lock the doors, that pin will lock the gas flap.

[mojo_monkey]

ahh, thanks i really need to get me a manual, haha.

[Bear]

You did not tell us where you live, but if in a warm climate,(hot summers and temperate winters) then 20W50 is OK. I live in SE Virginia and use Mobil-1 15W50 in my 1988 750, but syntetic or Dino oil is OK.

[mojo_monkey]

well im in sacramento, CA so it gets about 100 deg. F here in the summer. During the winter it isnt to unusual to see the temperatures around 32f, though that certianly isnt average. You guys think I should use something lighter?

[spiff325is]

20w-50 is for more miles and stuff. its heavier and thicker. 10w-40 is good I believe, I use castrol GTX.

[_1634_]

the biggest bmw nut ive ever known always used mobil 1 0w-30 (i think) in all his cars, from his e30 bmw (present day) to his porsche. and its the only thing he uses. any intelligence to this?

[Bmw1990]

I have to agree with spiff, I also use 10w-40, and i live in Michigan so the temp. varies constantly. 10w-40 is the way to go. I also use Castrol Gtx.

[Mystikal]

Geez, I know this guy doesnt have a manual, but the rest of you really should read yours.

20W-50 is good for 32 degress and up. If you're in California, use that. Hell, I need to use it for Toronto summers.

[Houston]

For years (I'm 50) I changed my oil and filter every 3,000 miles. When I bought a new car (2000 Camaro SS) I started using Mobile 1 and changing it at 7,500 miles. That was a hard transition, but now I use another synthetic (Amsoil) and change my oil once a year! I only put about 10,000 miles on it a year and I change the filter after 6 months, topping off the oil. I've had the oil analyzed, and it is fine. There are several studies on synthetics that say they are good over 18,000 miles and maybe 25,000 miles. That has been hard for me to believe, but it seems true.
Until I fixed the oil leaks in my 87 325, I used conventional oil. It has 300,000 miles on it and I'm debating switching to synthetic oil. I would use synthetic oil in any new car after a break in period. In older cars that leak or burn oil, probably not.
In my Camaro, I picked up .1 in the 1/4 mile by switching to synthetic oil, transmission fluid and gear oil. I autocross the 325 and SS. The SS runs cooler on synthetics.
I'm not very "green", but I do care about the environment. I'm more concerned about depedency on foreign oil supplies. Synthetics and their longer change intervals will help. Think about it.