Redline 5w50

[Maypo]

Originally Posted by dparm

Kinematic viscosity at 100 C is not the best figure for approximating operational viscosity. The oil might be at that temperature in the sump, but in places like the bearings it will be far warmer.

Use the HTHSV to compare operational viscosity. That being said, here are some 0w40 HTHSV numbers:

Red Line: 4.0
Mobil 1: 3.8
Pennzoil Ultra: 3.7
Liqui-Moly Synthoil Energy: 3.6
Royal Purple: 3.6
Motul 300V: 3.9

I have been using LM 10w60 for 25k miles and been happy with it. Prior to that it was Castrol 10w60, and using a quart between changes (6k). I am at 71k miles now.

Because the car's main usage is autocrossing, plus the concern about bearing wear, I would like to go to something lighter. I am leaning toward RL 5w40, but I haven't been able to find the HTHS or HTHSV of the LM for comparison.

[Maypo]

I haven't seen any discussion of oil choice as it relates to lifter performance. Any opinions or cautionary anecdotes about that?

[G80indy]

Originally Posted by Maypo

I haven't seen any discussion of oil choice as it relates to lifter performance. Any opinions or cautionary anecdotes about that?

Well....
Gunk and sludge are bad for lifters, VANOS and all the intricate oil passages in this race engine. Think about oil passages on the bucket cam tappets, oil jets on the pistons, the chain and hydraulic lash adjusters. All affected by clean or dirty oil.
Cleanliness! CHANGE THE OIL
don't be cheap and try to max your OCI.
And the better true synthetics/Group 4/5 keep the engine cleaner, IMNSHO

[Maypo]

All good advice. But, I was looking for commentary on the oil viscosities this thread was hashing.

[Doc Oc]

I've seen it stated in other forums that too thin of an oil in high rpm hydrolic lifter engines can cause bleed off...but when I mentioned it here the idea was poo poo'd I still think it's worth investigating.

[dparm]

Originally Posted by Maypo

I have been using LM 10w60 for 25k miles and been happy with it. Prior to that it was Castrol 10w60, and using a quart between changes (6k). I am at 71k miles now.

Because the car's main usage is autocrossing, plus the concern about bearing wear, I would like to go to something lighter. I am leaning toward RL 5w40, but I haven't been able to find the HTHS or HTHSV of the LM for comparison.

Lubro-Moly doesn't publish HTHS values. I've even tried emailing their tech departments in the US and Germany -- all they spout is the "minimum" for the grade, which is exactly what the tech sheets say.

[G80indy]

Originally Posted by dparm

Lubro-Moly doesn't publish HTHS values. I've even tried emailing their tech departments in the US and Germany -- all they spout is the "minimum" for the grade, which is exactly what the tech sheets say.

[admranger]

Originally Posted by dparm

People need to stop going off of rumors, conjecture, and anecdotal evidence.

If people did this, servers that host forums would only need 1gb of storage.

[dparm]

Originally Posted by admranger

If people did this, servers that host forums would only need 1gb of storage.

My comment is good advice even outside of online message boards. To your point, it's why navigating forums can be an exercise in futility: the real facts are often buried in a sea of anecdotal evidence and shitposts.

[STR8-6IX]

Originally Posted by Maypo

I have been using LM 10w60 for 25k miles and been happy with it. Prior to that it was Castrol 10w60, and using a quart between changes (6k). I am at 71k miles now.

Because the car's main usage is autocrossing, plus the concern about bearing wear, I would like to go to something lighter. I am leaning toward RL 5w40, but I haven't been able to find the HTHS or HTHSV of the LM for comparison.

You're concerned about bearing wear, so you want to go with a lighter oil?? Dude.. no. You've got it all wrong. Thicker oil will fill your bearings better and therefore provide better protection under a higher variety of driving conditions.

What the FUCK is up with you people taking BMWS SPECIFIC MANUFACTURER RECOMMENDATIONS and just throwing them out the window?? As if you guys know better then the engineers!! Stupid and ignorant!!

[Leonardo629]

Originally Posted by 6IX-F10-N52

You're concerned about bearing wear, so you want to go with a lighter oil?? Dude.. no. You've got it all wrong. Thicker oil will fill your bearings better and therefore provide better protection under a higher variety of driving conditions.

What the FUCK is up with you people taking BMWS SPECIFIC MANUFACTURER RECOMMENDATIONS and just throwing them out the window?? As if you guys know better then the engineers!! Stupid and ignorant!!

Many many oil analysis in this forum have shown a decrease in copper and lead when a switch to 0w40 is made, so no, thicker is not always better.

[admranger]

Originally Posted by 6IX-F10-N52

You're concerned about bearing wear, so you want to go with a lighter oil?? Dude.. no. You've got it all wrong. Thicker oil will fill your bearings better and therefore provide better protection under a higher variety of driving conditions.

What the FUCK is up with you people taking BMWS SPECIFIC MANUFACTURER RECOMMENDATIONS and just throwing them out the window?? As if you guys know better then the engineers!! Stupid and ignorant!!

Are these BMW Engineers the same infallible ones that designed the rod bearings for the S65 or a different set of engineers? Asking for a friend.

[Leonardo629]

Originally Posted by 6IX-F10-N52

You're concerned about bearing wear, so you want to go with a lighter oil?? Dude.. no. You've got it all wrong. Thicker oil will fill your bearings better and therefore provide better protection under a higher variety of driving conditions.

What the FUCK is up with you people taking BMWS SPECIFIC MANUFACTURER RECOMMENDATIONS and just throwing them out the window?? As if you guys know better then the engineers!! Stupid and ignorant!!

Many many oil analysis in this forum have shown a decrease in copper and lead when a switch to 0w40 is made, so no, thicker is not always better.