20w50 or 15w40 Brad Penn year round in Chicago?

[fdcg27]

When your BMW was new, the recommended oils were relatively thick conventionals, including 20W-50 down to around 4F.
Oils are better today and you probably don't run OCIs as long as BMW would have recommended back in the day.
This is an OHC engine, so the valve spring presures will be pretty low.
No need for a lot of ZDDP, and the oils of the days of this car's youth wouldn't have had much anyway.
Any 10W-40 would work well year 'round in this old guy.
It works great in my e36, which has a timing chain rather than the belt your 325e has and has much higher specific output.
The 325e isn't a powerhouse, after all.
You'd be fine in any weather with either Maxlife or Defy 10W-40.

 

[cnowak1]

Yea, the 325e is basically a diesel with it's rev limit

Fun little car though. The strange part though is that in the owners manual it says a 40 weight is only good to about 60 degrees which I know cannot be right? I had an e36 as well and I think it stated the same. Pretty strange as I know a 40 weight can easily handle summer temps.

 

[Quattro Pete]

Originally Posted By: cnowak1
The strange part though is that in the owners manual it says a 40 weight is only good to about 60 degrees which I know cannot be right?

It's the M20 engine, isn't it?

BMW has revised all their oil specs at some point when they introduced the Long Life specs. See the table below, especially footnote (4) that mentions your engine. It means that you can use an LL-01 oil, and that means Xw-40 and some Xw-30 oils, regardless of ambient temps. The M1 0w-40 mentioned earlier meets LL-01 spec and is a great, inexpensive, and readily available lubricant. There are many others, including the PU 5w-40 that I use in mine.

 

[cnowak1]

Yup M20, great find there thanks a bunch!