mobile1 0w 40 e30 318is

[Eric Happy Meal]

Next oil change ill be trying the Chevron 10w30 Super Synthetic.  I've heard very good things.

[318lotis]

well, at 7000 miles and 3 months later, im doing the mobil1 0w 40 again, very good oil

[lbreevesii]

NOTHING wrong with a ow-40 or a 20w-40...its just a matter of CLIMATE

[VegasKyle]

Someone posted a link to a good read about oil here.  I don't know where it is but the same article can be found at bobistheoilguy.com.  I made a post about the M42 and after someone provided actual sump temps it seems 0w-30 or even 0w-20 may be best.

[longms]

So what would be the best oil for a winter where temps average anywhere from 0-35 degrees? 0w-40???

Been hearing great things from all my buddies about Rotella. Will be trying this next.

[DesktopDave]

Our average winter temps in SW PA are from 0-30 degF.  I use synthetic 0w30 or 5w30 typically.  0w20 is too light for my high-mileage M42 IMHO.  I don't get any lifter clatter at all, even on ice-cold -10degF starts.  I use it year-round too, it's not really ever that hot here.  We can get a few 90degF days but they're unusual.

I do have some oil leaks, but I'm not taking the front of the motor off for that stupid timing chain case rear gasket.  Hot oil will find a way through any weak gasket regardless...I have yet to do a used oil analysis on the car, so I have no really solid numbers to back this info up.

[longms]

Yea, I live in Northwestern, OH. I am wondeirng if the 0w-40 would be a little bit thicker just to help with oil leaks? What would be the differences between said 0w30/5w30 or 0w40 oils?

[DesktopDave]

I usually listen for adequate flow at operating temps when figuring the best oil.  I used to put in a pressure gauge but I'm too lazy for that now.  I guesstimate with the second number for that, it describes the oil's viscosity when  hot.  From what I've read, the "base" oil is formulated from that warm temperature viscosity and then polymers (Viscosity Improvers) are added to increase cold flow. As a personal preference, I go with the smallest range of viscosity modifiers I can live with...5w30, for instance.  If I get cold-start lifter clatter I'll get something with more VI's, like 0w30.

With the BMW I started with 40-weight (10w40) & worked my way down to 30-weight.  The car didn't seem happy with 0w20, but that's just an opinion, no hard facts.

However, my minivan's 3.0 liter Ford V6 specs 0w20 year-round and seems pretty happy with that.  I always use Mobil1, IDK if it's a real synthetic but IMHO it's decent oil and the price is right (Wally World is usually around $28/5L).  My old motorcycle runs well on 10w40, but the clutch won't lock up properly unless it has non-"energy conserving" oil (the bike shares motor oil with a wet clutch & transmission).  Depends on the motor, that's what I'm trying to get at.

I'm also running thin oils to help with fuel mileage.  BMW uses a sliding scale for oil viscosity.  They spec 10w40 for expected winter temps (-20 to +50 degF) and 20w50 for expected summer temps (15 to 125 degF).  Very thick oil, that.  They don't make any adjustment for synthetics in original literature.

[VegasKyle]

I'm also running thin oils to help with fuel mileage.  BMW uses a sliding scale for oil viscosity.  They spec 10w40 for expected winter temps (-20 to +50 degF) and 20w50 for expected summer temps (15 to 125 degF).  Very thick oil, that.  They don't make any adjustment for synthetics in original literature.

I think 20w50 is way too thick.  The manuel was written 20 some years ago and I feel a lot has changed since then.  My speculation is the heavy oil was recommended to resist shearing and to preform under HTHS (high temp high stress).  Looking at the oils that fill BMW's current requirements they seem to place great importance on the HTHS number.  With todays oil you can get a high quality synthetic all the way down to 0w-20 or 0w-30 with a HTHS number around 3.0. bobistheoilguy.com has more information on oil that you could ever cram into your brain and is worth looking at.

[Ryann]

I think 20w50 is way too thick.  The manuel was written 20 some years ago and I feel a lot has changed since then.

I think BMW spec'd higher viscosity oil for proper lifter and chain tensioner operation, components who's designs have not changed (yes, I realize the tensioner piston was revised in the early 90's for better durability) in the last 20 years. What has changed is the design of these types of components in order to accommodate the use of thin oils.

Thin oil promotes better fuel economy, and that is why most if not all manufacturers have begun to specify it's use exclusively.  

Do yourselves and your engine a favor and pick the oil that is spec'd in your manual for the climate you anticipate driving in.

[VegasKyle]

I think BMW spec'd higher viscosity oil for proper lifter and chain tensioner operation, components who's designs have not changed (yes, I realize the tensioner piston was revised in the early 90's for better durability) in the last 20 years. What has changed is the design of these types of components in order to accommodate the use of thin oils.

Thin oil promotes better fuel economy, and that is why most if not all manufacturers have begun to specify it's use exclusively.  

Do yourselves and your engine a favor and pick the oil that is spec'd in your manual for the climate you anticipate driving in.

The whole argument over climate is stupid.  I don't care where you live the oil is going to be too thick at startup.  The oil thickness at operating temp is what matters.  As you can see from this chart the viscosity of all of these oils is the same where it counts.  Furthermore, how is an oil that is thicker at startup going to help the lifters and tensioner?  An oil that is resistant to flow is going to take longer to reach these parts at startup.

Where do you draw the line when it comes to what the manual calls for?  If I had a Stanley steamer that called for sperm whale oil or whatever is that what is best for the engine?

Oil type... Thickness at 75 F...Thickness at 212 F

Straight 30...... 250......................10
10W-30............100......................10
0W-30..............40 ......................10

http://m42club.com/forums/showthread.php?t=12307
If you have time you should read through this article.  I thought it was quite convincing.

[mr.vang]

0w40..crazy.. its like running with water at cold start. u must live in Alaska to need 0w40. 5 or 10 is fine.

[VegasKyle]

0w40..crazy.. its like running with water at cold start. u must live in Alaska to need 0w40. 5 or 10 is fine.

I had the same misconceptions as you until I read this article. ALL OIL IS TOO THICK AT STARTUP! Even 0w http://m42club.com/forums/showthread.php?t=12307

[mr.vang]

still, i'll never use 0 in CA unless i live where there is snow. thanks for the share though

[Ryann]

..how is an oil that is thicker at startup going to help the lifters and tensioner?  An oil that is resistant to flow is going to take longer to reach these parts at startup.

I wasn't referring to oil viscosity at startup, and in fact didn't mention at all. You did.

BMW is one of the most renowned engine designers/manufacturers in the world. I simply suggested following BMW's recommendations for oil selection, rather than making an uneducated judgement (AT LEAST from a mechanical standpoint) that the oil the engine manufacturer specified is "too thick".