OIL CHANGE MOBIL1 SYNTHETIC 0W40

[Schnellfahrer]

Greetings,
I discovered this site only a couple of days ago and I think it is marvelous!  For several years I  owned a 1992 K75RT which was totaled fortunately not with me on it.  It was parked and some lady backed into it at a pretty fast clip.  Since then I have owned a 1995 K75 with only 22K miles.   Now about engine oil.
It is my opinion that 20W50 is great for bikes with wet clutches and in fact that what it is made for.  50 is pretty heavy weight oil and was more designed for the transmission/wet clutch than for an engine with a dry clutch.  Yes, I know the gurus at BMW recommend it to be on the safe side with wet and dry clutches.
For a long time I have been using Mobil1 Synthetic 0W40 in both bikes and my 2004 Porsche Boxster. It comes in one and five quart bottles  which say: Recommended for European cars, MB, Audi and Porsche.  I have discussed this issue w/ an aircraft mechanic friend who rides a Ducati.  He is in total agreement with me on this subject.
I'd sure like to hear what you guys (and possibly girls) have to say about it.

[Laitch]

Welcome, Schnellfahrer! How about posting a photo of your bike in the Klassic K-Bike section?

The JASO MA and MB ratings indicate suitability ranges for wet clutches—not that I care. I've got a K75. :giggles  I leave frolicking in the oil pools to exotic bike owners, racers, and the tragically obsessed. :hehehe

[kioolt]

BMW recommended 20-50 way before they made any bikes with wet clutches.   I can't see them saying in 20 to 30 years we'll be making bikes with wet clutches so let's start recommended it now.

[F14CRAZY]

I run Valvoline or Castrol motorcycle 20w50 or 10w40 during colder temps (starts easier when it's below freezing).

I don't think synthetics are necessary. I know the K doesn't need the wet clutch protection of the oil I use but I figure it's a good, quality oil regardless.

At any rate I bought my Subaru Forester new and used pretty much only Mobil 1. With 197k miles it loves to drink Mobil 1 (couple quarts with 5k oil changes) so I've decided the extra cost isn't worth it, though I use synthetic in my wife's since she has a turbo

[stokester]

As an Airhead and K-bike rider I follow recommendations from those who have been riding and wrenching for a long time.

Snowbum has not steered me wrong yet and he recommends Mobile 15W50 based on his experience with starter sprag clutch problems.

http://bmwmotorcycletech.info/kstartersprag.htm

[RobP]

FWIW - I use M1 15w-50 in my K100RS, M1 0w-40 in my turbo'd Mini and Saab.  Buy in bulk at Costco or with the periodic coupons at AutoZone.

[beemerphile]

Winter oil threads are as perennial as the grass.

...Recommended for European cars, MB, Audi and Porsche.  I have discussed this issue w/ an aircraft mechanic friend who rides a Ducati. 

And this means he knows WHAT about old BMW motorcycles?  My dad was a rocket scientist at NASA but he wouldn't know jack about an old BMW.  None is so ignorant as an expert, once you get him away from the thing that he is expert about.  The best starting point is the factory recommendations.  They are made with much thought, a well-equipped laboratory, a knowledge of the machine, and a stake in your success.  As the machines age and new materials come along that were not available to the original designers, then the counsel of creditable experts with the particular machine may offer valuable insight.  Snowbum was mentioned and others exist as well.  What some anonymous poster on the internet with possibly fictitious credentials or experience thinks you should do is an angstrom away from useless.

He is in total agreement with me on this subject.
I'd sure like to hear what you guys (and possibly girls) have to say about it.

Is he in total agreement with you that 20W-50 is designed for bikes with wet clutches?  None is so smart as he who agrees with you.  Nor any as useless.  W.J. Wrigley said once that "when two men in industry always agree, one of them is unnecessary."  You have to listen to people who disagree with you to have any chance at learning something.  Otherwise, you are simply seeking to validate how smart you are.  In my case that answer is usually "not very."

[Medobson1]

Greetings,
I discovered this site only a couple of days ago and I think it is marvelous!  For several years I  owned a 1992 K75RT which was totaled fortunately not with me on it.  It was parked and some lady backed into it at a pretty fast clip.  Since then I have owned a 1995 K75 with only 22K miles.   Now about engine oil.
It is my opinion that 20W50 is great for bikes with wet clutches and in fact that what it is made for.  50 is pretty heavy weight oil and was more designed for the transmission/wet clutch than for an engine with a dry clutch.  Yes, I know the gurus at BMW recommend it to be on the safe side with wet and dry clutches.
For a long time I have been using Mobil1 Synthetic 0W40 in both bikes and my 2004 Porsche Boxster. It comes in one and five quart bottles  which say: Recommended for European cars, MB, Audi and Porsche.  I have discussed this issue w/ an aircraft mechanic friend who rides a Ducati.  He is in total agreement with me on this subject.
I'd sure like to hear what you guys (and possibly girls) have to say about it.

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[Medobson1]

Please don't be offended but Your opinion is improperly based. Based on how you've come to this opinion your not qualified technically to make the correct decision on what weight oil you should be using. There is no clutch inside the engine, so why would that play on your opinion? Second there is no gearbox Inside the engine, so shear forces play no part in the engine lubrication requirements.

That being said, BMW designed the tolerances inside the engine between bearing materials and rotating parts. The recommended oil viscosities provided inside your manual reflect their design tolerances based on environmental operating temperatures. The 0W40 does not apply to your bikes tolerances and operation conditions and you will be "under" lubricating your engine if you use that oil. In addition you may notice more oil leaks at seals and joints since the viscosity will be very much thinner than specified. Read the manual and follow the temperature chart. Mobil 1 is fine, just use the proper viscosity/weight recommended by BMW.


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[The Mighty Gryphon]

I love oil threads. 

C'mon guys don't hold back.

[Chaos]

Old K's really don't seem to care what you put in them.  Proof is the variety of what owners swear by.  Change it and don't run without it.  I run cheep name brand 10-40 car oil,  bike runs great.  Used to use BMW branded  20-50, bike ran great.  Only oil related failure I've seen was when the oil filter wasn't seated and the engine lost all oil pressure.  I use an AC-Delco PF-53 filter, but that could be another thread.

[The Mighty Gryphon]

Chaos, I hear you.  I'm running Shell Rotella T6 5W-40 in my bricks.  No problems, including the old 16V RS with 114,000 miles that had sprag issues before I started running the Rotella.  It's a heavy duty oil designed for diesel truck engines that routinely run a million miles before rebuilding. 

$21/gal. at Walmart.  Best price I could find for full synthetic.  My K75's don't use any oil at all(1 quart every 4000 miles), but the old RS is using about a quart every 800 miles, so it's nice to have great oil at a good price.

Those AC PF53 oil filters are cost effective which is important when you're doing annual oil changes on three bikes.  I can do all three for less than the price of one Hi-Flo.

Regarding oil filters, the worst are Fram.  I recall a filter test done by a fluid power  engineering society that found that Fram had the worst media and inconsistant manufacturing.  They either let everything through or caused so much pressure drop that lubrication was starved.  No way I would ever put one in any machine I wanted to keep.

[Chaos]

+1 on the Rotella T6, that my winter oil for the Ural which gets ridden at temps below zero.   Synthetic make starting MUCH easier!

[Schnellfahrer]

Hello MEDOBSON1.  Thanks for your lengthy explanation.  FYI it takes a lot more than your friendly dissertation for me to be offended.  Common sense tells me that, especially in very cold weather, 0W40 oil starts flowing a lot faster and thus lubricates just about immediately then the syrupy sluggish 20W50.  I have used the Synthetic  0W40 for over 12 years and have not noticed any leaks, smoke or other unpleasantness. In fact the few problems I have encountered both on my 1992 K75RT as well as on my 1995 K75 were totally non engine related. Again, I think 20W50 is wonderful for bikes w/ a wet clutch but puts undue and unnecessary strain on a dry clutch K75.  However, I respect and welcome different opinions.

[BlitzenGruv]

Oil?
Standard answer is Castrol R, and change after every race.
With a dry clutch I don't guess it matters much, but BMW specifies 20W50 so that's what I use. Mobil V-twin works in everything I have.

[Martin]

 :yow Oil you have to put oil in them, nobody told me, where do you put it? I have 2 gallons of peanut oil will that do?? :dunno

[BlitzenGruv]

:yow Oil you have to put oil in them, nobody told me, where do you put it? I have 2 gallons of peanut oil will that do?? :dunno

Might not do much for lubrication, but it will fuel a Diesel engine very well. Petroleum is the "alternate" fuel for Diesel. Rudolf designed his engines to run on peanut oil.

[Martin]

 :2thumbup: Right will start tomorrow on converting the Brick to Diesel, so I can use my 2 gallons of peanut oil. Greatly appreciate the help.
Regards a relieved Martin.

[YoungEngineer]

I used 10-40 for some time but noticed excessive consumption at highway speeds and smoke on startup. I've gone back to 20-50 which has almost no consumption, no smoke and low engine noise.

[Medobson1]

Hello MEDOBSON1.  Thanks for your lengthy explanation.  FYI it takes a lot more than your friendly dissertation for me to be offended.  Common sense tells me that, especially in very cold weather, 0W40 oil starts flowing a lot faster and thus lubricates just about immediately then the syrupy sluggish 20W50.  I have used the Synthetic  0W40 for over 12 years and have not noticed any leaks, smoke or other unpleasantness. In fact the few problems I have encountered both on my 1992 K75RT as well as on my 1995 K75 were totally non engine related. Again, I think 20W50 is wonderful for bikes w/ a wet clutch but puts undue and unnecessary strain on a dry clutch K75.  However, I respect and welcome different opinions.

The brick engines have been tested to be the coolest running engines in all of MC when they were made. Not because they are dry clutches but because they are designed with a separate transmission with its own gear oil sump, therefor there are no shear forces on the engine oil.  That is what is preventing your practice of using a very light weight lubricant from causing problems in the engine. In truth the wear really occurs in that engine when it is first started. This is when most of the wear occurs to the bearings.

If the crank and rods were suspended by needle or ball bearings, the weight of the oil would make Little difference in the wear of the bearings. In the case of the K engines, which employ plain bearings, the engineer designs the size and surface area of the bearings, including the tolerances between the bearing material and the rotating surface materials. When it's all said and done the weight / viscosity is defined and tested on running test mule engines. ( 1980s time frame methods). The other factor is the oil pump and its output pressure using a 0/30 weight oil may not be adequate with an ambient temp above summer days. Basically, the results confirm the bearing wear attributes and a decision is made on what to specify confirming the decision with lube oil engineers being involved based on operating temperatures and bearing temperatures.

I will go out on a limb and believe no 0/30 oil was tested on these engines in the 1980s. I've seen the recommended oil charts before but don't have one handy at work. I do know that 10/40 is on the chart but don't recall if a 5/30 or 5/40 is. I do know that application of 10/40 is very limited to a low temperature range, below 50 degrees. So a 0/30, even if recommended would be limited to deep freeze riding!  You are probably not seeing the extra wear your putting on your engine but it's happening, every time you start your bike.  I would not use that weight oil in that vintage K bike, your rolling the dice.

Mike Dobson
Machinery Controls Engineer
NAVSEA


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[Schnellfahrer]

Thanks Mike.  It is not quite clear to me why you are now also throwing these other oil weights into the discussion
  such as 5W30, 10W40, etc.  The only two we're comparing are "your" 20W50 and "my" synthetic 0w40.
I completely agree with you when you say:"In truth the wear really occurs in that engine when it is first started. This is when most of the wear occurs to the bearings".   Wise words indeed and I couldn't agree more!
It stands to reason, doesn't it, that it takes a while for the thicker and slower 20W50 to begin fully lubricating in low temperatures especially at start up.  No problem there with the initially thinner 0W40 which gets to the bearings without delay with its much lower cold cranking viscosity.
As I have mentioned previously I have used the synthetic 0W40 for over 12 years in two different K75s without noticeable oil consumption, leakage, smoke or engine problems.  Lets just say we agree to disagree on this subject, shall we?

[Laitch]

The path of lubrication discourse is always a slippery slope.

[thecableguy]

 :hehehe

[wmax351]

There is some logic for 0w40 if you are doing really cold temperatures. 5w40 is okay too. I was running 5-40 rotella during the winter when I was riding below freezing. 15w50 is good down to the 40's, iirc the charts they provide.

K bikes have air cooled oil, with fins on the oil pan. This means the oil temperature is somewhat dependent on the ambient temperature and airspeed. So that explains the 40 weight spec at low temperatures, and 50 weight at normal and high ambient.

On the other hand, my subaru has a oil-water cooler, which also serves to heat the oil in winter. It will be held at 190-210 all year, from below zero to hot summer days. So it specs a 30 weight oil, either 5w30 or 10w30 all year. There's no reason to go to a 40 weight in the summer, unless the engine is pretty old so the clearances are larger.

The first number is the cold viscosity: lower is better in regards to startup wear and ease of starting. It has no effect once at operating temperatures, other than that the wide range oil tends to not have the durability of narrower range oil.

[F14CRAZY]

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 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?