Official OIL THREAD

[pifane]

Hi everyone!

Ive read a lot on the internet regarding what kind of oil I have to put in my M42...

I also called "BMW VILLE DE QUEBEC" and they told me that my car require castrol 5W30.

Another people recommend syntec oil, but other people said that it not good for the gasket and make a oil leak...

Another people recommend Castrol 20W50. But, another people said " 20w50 is NOT recommended in an M42 (or any other DOHC BMW engine) it will starve the HVAs (lifters) 10w30 or 40 is fine for the M42 (latter DOHC engines require 5w30). "

SO, WHAT IS ORIGINALLY RECOMMENDED BY BMW FOR THE 1991 318I M42B18 ENGINE???

[batsbats]

I read a lot of the 12v e30s use the Castrol 20w50.  

In the manual it says 15w40 I think.  I've been using Mobil1 15w50.  It runs a little slow as the oil warms up.  

Since you're up north, I would run something light like 10w30 or w40.

[mkodama]

The hard part is that the original oil weights suggested when the car first came out are a little different then they are now. Synthetic wasn't common back then and even conventional oils have changed a little(for the better).

My suggestion is to use oil with a BMW LongLife approval. All BMW engnes with the exception of the S54, S65, and race motors are designed to run on this type of oil. The most common oils are BMW Castrol 5w-30 from the dealer or Mobil 1 0w-40.

If gaskets do start leaking from using synthtic, that means the gasket needs to be replaced and the oil is just doing it's job of dissolving engine sludge.

And you want something with a 0w or 5w in the weight of the oil, especially I you live in colder climates. This means that the oil will act like a thinner oil when you first start up your car and the engine is cold. If the oil is say a straight 40 weight, at -10 C the oil will be like cold maple syrup and will barely even circulate through your engine(which means lots of wear).

[AcSchnitzer318is]

Mobil 1 0w40 here but I don't know what the "official" oil to use is... if there is one.

[tjts1]

It doesn't really matter what was originally recommended way back in 1991. Engine oils have gone through about 8 different API spec generations since then. You're better off just searching this forum for the other million or so threads on the subject to see what other people are using.

[EN318isPDX]

It doesn't really matter what was originally recommended way back in 1991. Engine oils have gone through about 8 different API spec generations since then. You're better off just searching this forum for the other million or so threads on the subject to see what other people are using.

but this thread is OFFICIAL

[mkodama]

Why do so many people use 50 weight oil in their E30's?  Like, it's a bit of a trend I've noticed, that all the people with newer cars use what BMW recommends(usually), but the people with the cars from before 1990 use ridiculously thick oil?

[Jimmy Lewis]

I suppose it could quiet down chain noise a bit but I just get over it and run 10W30, usually Castrol, but I usually just buy what is on sale. As old as my motor is, I really don't care.

[halcron]

For me, I am using Redline, Torco and Amsoil 5W40 and 10W40 oils. HAve been using them for quite a long time already. My M42 seems to be in harmony with it.

[mkodama]

For me, I am using Redline, Torco and Amsoil 5W40 and 10W40 oils. HAve been using them for quite a long time already. My M42 seems to be in harmony with it.

I've read a lot of really good stuff about Redline.  Apparently both Redline and Amsoil claim to surpass BMW standards but just haven't gone through the steps to get the approval since it costs time and money.  Never heard of Torco lubricants though.

[nicknikolovski]

I've tried several oils. Castrol GTX3 15W40 - ok, Castrol Magnetec 10W/40 - shit,      Mobil 1 Synthetic 5W/50 - very good, Mobil Synth S 10W/40 - currently in my engine - very good.

I think I will stick with 10W40 oils. You need to really get oil based on temperatures where you live. Its not very thick so it will get into the lifters quickly and its not too thin so it shouldn't cause leaks. I got an oil leak when I used the 5W50, went back to 10W40 and cleaned it up. Can't see a leak anymore - strange?

[mkodama]

I've tried several oils. Castrol GTX3 15W40 - ok, Castrol Magnetec 10W/40 - shit,      Mobil 1 Synthetic 5W/50 - very good, Mobil Synth S 10W/40 - currently in my engine - very good.

I think I will stick with 10W40 oils. You need to really get oil based on temperatures where you live. Its not very thick so it will get into the lifters quickly and its not too thin so it shouldn't cause leaks. I got an oil leak when I used the 5W50, went back to 10W40 and cleaned it up. Can't see a leak anymore - strange?

What was your basis for determining which oils were good and which were bad?

[Wizard]

This is straight from the Mobile 1 website:
http://www.mobiloil.com/USA-English/MotorOil/Car_Care/Vehicle_Chooser/VehicleChooser.aspx?option=2

Current Vehicle:
Year:      1991
Make:   BMW
Model:   318is
Engine Type: 4cyl. 1.8 Liter Naturally Aspirated
 
Mobil 1 0W-40

A fully synthetic motor oil, Mobil 1 0W-40 with SuperSyn Technology exceeds industry standards and the major leading builder requirements, enabling the product to keep performing well after conventional oils cannot. Mobil 1 is recommended by leading car manufacturers as initial fill.

I personally use Mobil 1 15W-50. Mostly because of the heat here in SW Florida and the approx 250k on the odo. Summertime temps average 95.

What I find amazing is that some of the newer Jap 4 cylinder models use 0W-20 or 5W-20...Damn thin..

[P. Kennedy]

Shell Rotella T 5W-40.  Search this forum and you'll get confirmation from a true oil guy.

[nicknikolovski]

My engine ran better with the mobil oils, and the mobil oils looked cleaner on the dipstick after 5,000km over the castrol oils.