OIL CHANGE MOBIL1 SYNTHETIC 0W40

[Chaos]

Isn't there an oil temp gauge that goes in the oil fill for motoboxers?

there is for boxers, not bricks. Not a straight shot into the sump. Oil temp is pretty well controlled by the engine's liquid cooling.  Complete warm up probably takes a good 10 mile jaunt.

[wmax351]

Well there's initial startup and then normal operating temperature to worry about.

What about when it's like near freezing and you're having to do 70+ mph after only a couple minutes or a mile of run time and the temp gauge is still pegged on the low end? Is the multi-viscosity aspect of like the 10w40 I run in colder months taking care of that?

I think that is part of the advantage of 10w40 or 5w40 (yay for cheap rotella t6). Both ends are thinner, accounting for the lower start and operating temps. You could probably pull up a viscosity temp curve online.

With regard to the temp guage being pegged, after a mile or so, it's probably in the low hundreds or so. The gauge is designed to show the operating range roughly.

I like how it was pointed out that our oil pans are air cooled and ambient temps likely have a role on operating temperature viscosity. I suppose an oil temp gauge would be the best way of figuring that out.

Isn't there an oil temp gauge that goes in the oil fill for motoboxers?

There are temp gauges that go in the oil fill on a airheads. Doesn't work on K's though. You could put one in the oil pan pretty easily if you wanted though: just take it off, drill and tap. They probably sell an adapter that puts one in oil drain plug as well.


https://www.amazon.com/Docooler-Digital-Temperature-Celsius-Warning/dp/B00FDMKQOA/

https://www.amazon.com/Equus-9848-Pressure-Electronic-Temperature/dp/B001DKM4PU/  <- Not sure if this is the right size for the K bikes, but same idea

[Medobson1]

First let's agree that the oils designation for viscosity is the first number (0,5,10,15 or 20). The second number is the ability or range of the oil to remain the stated viscosity within a standardized design range over a given temperature span. So back to the lower viscosity numbers. Yes if you are operating the K bike engine as discussed in a low temperature range you must reduce the oils "weight" or viscosity. Canadian riders may never use 20W 40 or 50 oils. In winter months it could actually cause an engine failure because the oil would not pump through the system. Same is true for summer hot weather in Arizona a 5 or 0 weight oil would thin out and could fail a bearing, most likely a cam lobe or camshaft plain bearing surface. Now back to the oil viscosity chart in your manual. Note the temperature range of each oil viscosity. This is a generic chart and does not represent synthetic oil properties. It is truly a representative chart based on design standards for a mineral oil based lubricant. Synthetics now have much wider operating bands or ranges than when these bikes were designed.  As we all know the primary purpose of engine oil is to provide a lubricating film between moving parts, despite the fact that synthetics perform all the other attributes that engine oils do better than conventional oils the weight of the oil remains a constant property of both types of oils. How the engine was designed and its tolerances is what defines the required weight or viscosity of the oil specified.

In my profession we are constantly evaluating engine lubrication and lubricants for our large Diesel engines that propel small and large warships. Some of these engines were designed before, at and since the Brick engines were designed and built. The more modern an engine typically is, the more restrictive the lubricant requirement is. This seems to be a trend today as fuel efficiency drives designers to reduce frictional losses.

When it comes to gear boxes and synthetics it's a whole different discussion. It's all about shear factors and molecular breakdown.

In the end it's a simple matter of asking BMW NA Technical support about your theory. They have access to the design info to make the call, right or wrong.


Sent from my iPhone using Tapatalk

[The Mighty Gryphon]

Nice post Medobson1.  If I might add a bit to help clarify the viscosity discussion.

On a multi viscosity oil the W number is the basic viscosity.  This is the viscosity the oil in the bottle naturally has.  By using a lower viscosity base oil you will have more flow and less pressure drop through the system(meaning the last bearings in the circuit will will have more oil) at low temperatures.   The problem with a low basic viscosity is that as the engine gets warmer the oil will thin out to where it doesn't lubricate any more. 

The second number is the viscosity of the oil at the engine's operating temperature which is defined as 100 degrees C(212 F).  The higher this number is, the thicker the oil will be at the operating temperature.  Up to a point, the higher the number the better the lubrication.  However, if the viscosity is too high, it will be too hard to pump through the engine at operating temperature and downstream bearing will suffer.  This second number is achieved by adding viscosity extenders which are additives that prevent thinning as the oil gets hotter.

The problem with viscosity extenders is that as they "cook" out of the oil the oil gets thinner, and lubricates less.  This is one of the processes that causes the oil in your engine to "wear out".   Modern oils have better extenders that last longer so service life is longer and you can go more miles between changes. 

The result is that when you look at the W number you have a choice; less lubrication at low temperature vs. shorter service life.  The wider the gap between the two numbers the more extenders have been added and the faster the oil will "wear out". 

The hard part is finding out how fast the extenders breakdown.  By buying a major brand and changing at reasonable intervals I would think that we will be changing before the oil stops protecting the engine.  That is why I use Rotella T6.  It is a heavy duty oil designed for heavy duty diesels that owners want to run as reliably as possible for up to a million miles or more in a wide range of operating conditions. 

[Martin]

 

[Laitch]

This thread is what happens when not enough people have friends with Ducatis. :musicboohoo:

[Filmcamera]

Ok I have no friends with Ducati's (though at least one acquaintance, does that count?) so I have a question. I live in Costa Rica where a really cold evening is 60 fahrenheit and the average day is around 80f and a hot day is close to 100f. Does this mean that all this very scientific thread is irrelevant to me and I should just use whatever happens to be available or does it still matter?  I ask because I have to change the oil tomorrow and was thinking to getting 10 W 40 like I run in my car (a 2012 VW Passat)

[Chaos]

Take your lowest expected temperature Fahrenheit and divide by 3, and divide your highest expected temperature by 2.  This will give you a mathematically derived suggested oil viscosity.  Adjust to whatever you wanted to use anyway.  I just made this up so it must be true.

[The Mighty Gryphon]

Take your lowest expected temperature Fahrenheit and divide by 3, and divide your highest expected temperature by 2.  This will give you a mathematically derived suggested oil viscosity.  Adjust to whatever you wanted to use anyway.  I just made this up so it must be true.

Having just seen it on the interwebs I know it is true. 

I don't have any friends, let alone friends with Ducati's.  Still trying to decide if I even want any.

[Laitch]

I live in Costa Rica where a really cold evening is 60 fahrenheit and the average day is around 80f and a hot day is close to 100f.

20w50

[beemrdon]

I use Mobil 1, 15-50 and buy it in a 5 qt jug from Wally World for $22.88. I fill to 3.5 quarts.
I switched from Valvoline M/C 20-50 dino oil because I had experienced "blow by" upon hard deceleration (bad smell) while using it.
Since switching to the Mobil 1, I haven't smelled it at all.    :cowpoop:



BTW, (doing my best Ed McMann) ..... WHEEEEEEEEEEERRRRE'S JOHNNY?

[nadrol]

old thread, I know... but pertinent data to follow up on Medobson1's info

First, oils have to fall within a range to be labeled a certain weight, so actual viscosities can vary quite a bit between manufacturers.
40W viscosity range at 100c: 12.5 to 16.3 cSt
50W viscosity range at 100c: 16.3 to 21.89 cSt

And some examples:
Type, Viscosity 40c (cSt), Viscosity 100c (cSt)
Mobil 20w50,           185, 20.5
Mobil 15w50,           125, 18.0
Mobil 20w40,           118, 14.2
Mobil 10w40,           89.3, 13.3
Mobil 5w40,             80.0, 13.7
Mobil 0w40,             78.3, 13.8   

So we see that the hot viscosity varies a bit depending on the basic (cold) weight, with a higher basic weight typically having a slightly higher hot viscosity. Otherwise, a 0w40 is pretty much the same as a 20w40 at running temperatures where it matters, until the oil degrades. Mobil still claims 10,000 mile service intervals, but that seems a bit far fetched; I'd like to see viscosity data at 1000mile intervals up to 10k miles, but I don't see anything like that online right off.

Anyways, Its getting into the colder months in Colorado (30f overnight at 60f highs), so i'm switching from 15w50 to 0w40 for a few months.