Let's compare oils

Shredicus wrote

Just want to put some in my differential because the slip is currently being limited and I do not like being told what to do

Townending wrote

After reading a few of the bearing issue threads, and reading that it is caused by inadequate oil lubrication, I didn't feel comfortable with 10W-60 for DAILY DRIVING. I would be more than happy to use 10W-60 on the track.

Using OEM Castrol and Shell fluid, I was never able to get the oil temp marker to stay at 210F, it would raise to 210F while I was on it, but drop down to ~195F when I would take it easy. In my eyes, this tells me I'm not getting the oil up to ideal operating temp.

I then read about the users (one being a very close friend) who switched to Mobil 1 0W-40 and saw acceptable wear on their bearings. (Can't say for sure if they were lucky to have minimal wear, or if the oil actually did help.)

Now, with the above information, I started comparing oil viscoisties. After seeing the numbers, I decided that Mobil 1 0W-40 was too thin for my liking. I was worried that if I did choose to really push the car, that the 0W-40 would not be thick enough once the temps started climbing.

I then focused on AMSOIL 5W-50 Signature Series, Redline 5W-50, and Motul 5W-50. Motul was a PITA to get, so that was dropped from my choices.

Back when I made this decision, AMSOIL had not introduced their new formula. At the time the stats on paper for AMSOIL were much closer to Redline, they were almost the same.

Since I was looking at two great oils with very similar specs (based on tested specs), I simply went with the one that made more sense financially. I buy AMSOIL in a 12QT case for $102* shipped (1-Day Shipping), bringing it to $8.50 a quart. Where as ordering Redline would have cost me $13 a liter, and I would of had to pay a ton for 1 day shipping through ECS (My store of choice for Redline).

After my first oil change with AMSOIL, I noticed the engine had a much smoother rev pulling out of my driveway after a cold start. Not only that, but oil temps stay at 210F for light daily driving / spirited driving.


And there you go, my thought process. Again, I have no concrete evidence saying 10W-60 is not ideal for DD. But after my research, I felt most comfortable with AMSOIL or Redline 5W-50

Townending

jeff@autocouture wrote

Thank you for all the info and documentation!

could you possibly check
Royal Purple XPR 10w60
Redline 10w60
redline 10w40

Thanks!

dparm wrote

Red Line 10w60 is on the thick side for its grade and won't thin out much with use:
https://www.redlineoil.com/10w60-motor-oil

I'd probably thin it out with a bottle or two of one of their other oils like the 5w40 or 10w40 -- get the HTHS down by 10-12% or so.

e92m3jb wrote

so which oil is better?

jeff@autocouture wrote

Thank you for all the info and documentation!

could you possibly check
Royal Purple XPR 10w60
Redline 10w60
redline 10w40

Thanks!

Dr. Dre wrote

I would go with Total. I had a meeting with the Total reps just this week. They were saying that US oil requirements are a joke. European requirements are much higher.

They also said that their 10-60 still have all the original additives. However, the EPA keeps forcing oil manufacturers to take out more and more of the additives.

ham_sammich wrote

I want to add some recent advice from an experienced S65/85 engine builder. Redline 5w50 is his recommended oil for both stock and stroker applications. he states it helps the engine run cooler, and the 5w50 offers better protection under both DD and hard use.

I run the Motul 8100 10w60 and noticed 2 things.
1. I conistantly hit 210 during DD.
2. I run 20-30 degrees cooler on the track.
I would see 220-230 during DD with LM 10w60 and see 260-270 on track, in cool weather.

Im debating the switch to 5w50 given the recent advice, but Im skeptical.

admranger wrote

ham_sammich wrote

I want to add some recent advice from an experienced S65/85 engine builder. Redline 5w50 is his recommended oil for both stock and stroker applications. he states it helps the engine run cooler, and the 5w50 offers better protection under both DD and hard use.

I run the Motul 8100 10w60 and noticed 2 things.
1. I conistantly hit 210 during DD.
2. I run 20-30 degrees cooler on the track.
I would see 220-230 during DD with LM 10w60 and see 260-270 on track, in cool weather.

Im debating the switch to 5w50 given the recent advice, but Im skeptical.

Thanks for the info on the Motul 8100. 20 degrees cooler on track is significant.

I loved Redline oil when I raced, but it left the engine a lot of varnish in the S50 I was running. Granted, the engine ran stupid hot until I went to prepared class and could pull the condenser.

5w-50 probably is too thin for me now that I have BE Bearings in the car (though the mains would probably prefer the thinner 5w-50).

ham_sammich wrote

I want to add some recent advice from an experienced S65/85 engine builder. Redline 5w50 is his recommended oil for both stock and stroker applications. he states it helps the engine run cooler, and the 5w50 offers better protection under both DD and hard use.

I run the Motul 8100 10w60 and noticed 2 things.
1. I conistantly hit 210 during DD.
2. I run 20-30 degrees cooler on the track.
I would see 220-230 during DD with LM 10w60 and see 260-270 on track, in cool weather.

Im debating the switch to 5w50 given the recent advice, but Im skeptical.

jc68 wrote

Great information. I don't DD my E92 M3, drive it every 2 weeks or so. Which oil properties should I look for the best cold start protection and leaves a protective coating of oil on the bearing surfaces, minimizing dry start?

dparm wrote

I'd continue using a 10w60 just like BMW calls for. Unless you got some sort of pre-start lubrication system (like an Accusump), oil choice won't really change much if the car is sitting for two weeks.

seevin wrote

I have found some test results with multiple oils:
https://docs.google.com/spreadsheets/d/1fbb9qtL-yWlzDPLzvxzpF01gRRtH8fKxeVtXt6HPpgg/edit#gid=0
Here is the testing method:

Not sure how relevant this test is, but in this comparison Motul seems to achieve the best results of 10W60 oils.

Also, I have found that Liqui Moly 10W60 has HTHS value of about 3.5, which seems to be very low.

Shredicus wrote

I don't generally see a lot of positive feedback surrounding these types of wear tests but I suppose it's a data point.
The HTHS of 3.5 sounds impossibly low for the Redline 10w60

seevin wrote

I wrote Liqui Moly, not Redline. Check the product information, they claim it's >=3,5. Does this mean this oil provides less protection than others ovarall? Not sure how to read it, as it is a parameter measured in a very high temperature of 150C.
https://pim.liqui-moly.de/pidoc/P000342/1390-SynthoilRaceTechGT110W-60-21.0-en.pdf[/QUOTE

Their tech support is very responsive and informative, email them for clarification. I had a similar question about their MRV result and it turns out they are being conservative. MRV and HTHS are both rather variable so often averages are listed IIRCC.