03 R1150RT Oil temperature vs type, weight, brand

[RogerC60]

I'm not trying to start another oil thread, I just noticed something and wondered if anybody has an explanation.

 

Up until a couple of days ago I've been running Mobil 1 15W/50 and my oil temperature gauge rises to 6 bars and holds there. This no matter if it's a cold day or a hot one.

 

A couple of days ago I did an oil change and put in Castrol GTX 20W/50. Since then the oil temperature gauge settles at 5 bars and goes no higher. The bike is running the same as before (maybe just a tad quieter) so I'm not concerned... just curious.

 

[SAS]

I would tend to think that the 20W-50 is not holding as much heat as the 15W-50.   But are we comparing apples to apples?  M1 15W-50 is synthetic and the C 20W-50 is conventional oil.  Why would you change from a synthetic to a conventional oil?  Just curious.

[dirtrider]

On ‎7‎/‎24‎/‎2019 at 10:26 PM, RogerC60 said:

I'm not trying to start another oil thread, I just noticed something and wondered if anybody has an explanation.

 

Up until a couple of days ago I've been running Mobil 1 15W/50 and my oil temperature gauge rises to 6 bars and holds there. This no matter if it's a cold day or a hot one.

 

A couple of days ago I did an oil change and put in Castrol GTX 20W/50. Since then the oil temperature gauge settles at 5 bars and goes no higher. The bike is running the same as before (maybe just a tad quieter) so I'm not concerned... just curious.

 

 

Morning  RogerC60

 

First, I am surprised that you didn't/don't get some variations  in the temperature gauge reading on a hot vs a cold day as that usually varies slightly.

 

As for your new oil change showing a different gauge reading?-- that is possible as you are comparing old used oil of a slightly different viscosity weight to new un-sheared oil motor oil.

 

Remember that the temperature gauge on the dash  is showing the  cooling oil circuit after it has picked up engine heat but before the oil goes through the oil cooler.

 

Ride the bike for a while to see if the oil temps return to what you are used to  after the oil shears a bit & becomes used.

[RogerC60]

5 hours ago, SAS said:

Why would you change from a synthetic to a conventional oil?  Just curious.

 

Actually I wondered that myself after I got done pouring it into the motor. Long ago I got used to buying Castrol GTX 20W/40 for my motorcycles. I think this was just a brain fart. At least I got the 20W/50 :-)

 

[AndyS]

You know, in my old 1150, I found it always seemed to run better on good old Castrol GTX than the synthetic oil. I don't know why. One big bonus is that Castrol GTX is a fraction of the cost too!

Nothing too exotic in these engines and they cope well with the ambient temperatures in my part of the world.

[RogerC60]

22 minutes ago, AndyS said:

You know, in my old 1150, I found it always seemed to run better on good old Castrol GTX than the synthetic oil. I don't know why. One big bonus is that Castrol GTX is a fraction of the cost too!

Nothing too exotic in these engines and they cope well with the ambient temperatures in my part of the world.

 

Interesting that you mention that. I also had thought that the motor was running quieter on the Castrol GTX, but I also thought maybe I was just imagining it.

 

[SAS]

17 hours ago, RogerC60 said:

 

Actually I wondered that myself after I got done pouring it into the motor. Long ago I got used to buying Castrol GTX 20W/40 for my motorcycles. I think this was just a brain fart. At least I got the 20W/50 :-)

 

If your bike is ok with the conventional oil then why not use it, if you are getting good results from its use.   As AndyS said it is a" fraction of the cost".  I have been using 20W-50 Castrol conventional oil in my rig for years.  My oil of choice is Castrol.  That is all I use and have had great service overs the years and have never had any engines puke because of it.   With its use in both bikes and cages.  My thought is that, it is the life blood of the engine, changed on a regular basis and you can't go wrong.  That is probably true with any oil on a regular basis, but I like the Castrol the best. 

[legarem]

My R1150RT 2003 takes about 1 liter of oil per 3000 kms. It has 130 000 KMS. I use Mobil one 15W50.  I always used this oil. Previous owner told me he was using mineral oil and he never had to add oil. With what Andy wrote, i'm tempted to return to Castrol GTX 20W50. I'm still asking me why Caltrol GTX should make motor mechanically more quiet.  I always tought synthetic oil made less friction in the motors than mineral oil. Normally, if the motor does less mechanical noise with GTX. than Mobil 1, it means that GTX does less friction in the motor than Mobil 1. This destroy all my thoughts about oils.  If someone has an explanation, this should be great.

[Sam Taylor]

On 7/30/2019 at 8:42 AM, AndyS said:

You know, in my old 1150, I found it always seemed to run better on good old Castrol GTX than the synthetic oil. I don't know why. One big bonus is that Castrol GTX is a fraction of the cost too!

Nothing too exotic in these engines and they cope well with the ambient temperatures in my part of the world.

I learned in my 94 1150RS days that synthetic oil in the motor had no short term benefits.  It also tended to use more between changes. 140K miles when I sold her.  Consequently, I've always used 20/50 Dino oil in my 02 1150RT, which uses about 1 quart/2500miles.  So it changes itself.  I do give it a new filter every 6K.  120K.

[RogerC60]

Thanks, everyone, for the advice and comments. And I really really don't want this to become an "oil thread". I'm going to watch what happens on my oil temperature gauge as the oil gets some miles on it.

 

[legarem]

Roger. Your thread made us discover something I or we didn't thought about our oilhead motors. (GTX vs synthetic)

I hope someone will have an answer to this dilemma.

[AndyS]

13 hours ago, legarem said:

 

I hope someone will have an answer to this dilemma.

 

What dilemma?

[legarem]

1 hour ago, AndyS said:

 

What dilemma?

 

Why GTX makes the motor quieter than Mobil 1 as synthetic oil is 'supposed' to lower the friction between parts compared to mineral oils.

[AndyS]

I guess it's because it is thicker and it also attenuates the transmission of clacks and clunks.

[RogerC60]

3 hours ago, AndyS said:

I guess it's because it is thicker and it also attenuates the transmission of clacks and clunks.

That would be my guess as well.

[dirtrider]

Morning___

 

Everything else aside between synthetic & conventional oil -- We 'are' comparing well used (well sheared) synthetic oil to unused (un-sheared) conventional motor oil. This alone can make a significant difference.

 

Then, we are also comparing  a 15 weight  (base weight)  synthetic to a 20 weight  (base weight) conventional, and  neither oil ever gets any thicker than their base weight rating (@0°c) but both do (should anyhow)  'thin out'  to what a 50 weight oil would at 100°c. 

 

[SmokinRZ]

I just drained the oil in my R1100gs and screwed in a new BMW filter.  I bought some Castrol 20W50  based on this thread, but then I started second guessing my decision.  A little research revealed that GTX is not recommended for flat tappet cams.  I know we don't have flat tappet cams but I'm still thinking maybe I should get the motorcycle specific Castrol 20W50.  Should I stop fixating and just dump the GTX in?  I don't go beyond 4K miles between changes.                

[dirtrider]

8 hours ago, SmokinRZ said:

I just drained the oil in my R1100gs and screwed in a new BMW filter.  I bought some Castrol 20W50  based on this thread, but then I started second guessing my decision.  A little research revealed that GTX is not recommended for flat tappet cams.  I know we don't have flat tappet cams but I'm still thinking maybe I should get the motorcycle specific Castrol 20W50.  Should I stop fixating and just dump the GTX in?  I don't go beyond 4K miles between changes.                

 

Morning SmokinRZ

 

Technically your BMW 1100 has flat tappets (just has short push rods & high mounted cams). The saving thing on the flat tappet thing is that your engine is a 4 valve so the valves are small & use fairly light valve springs so the cam lobe scuff  loading is fairly low.

 

On the Castrol GTX 20w50 being acceptable? -- Darn good question!

 

Most of the newer bottles of  Castrol GTX 20w50 are rated SN so that pretty well tells us  the ZDDP level is fairly low for your older boxer engine. (BMW published a service bulletin long ago to use SG/SH rated engine oil as SG engine oil has a LOT of ZDDP anti-wear additives in it). Problem is, the older SG/SH oil rating is obsolete so even newer engine oil that "could contain" a high enough ZDDP content to meet the older SG/SH standard is not tested for, & can't now be rated for, the obsolete SG/SH standard.

 

The possible good about the  Castrol GTX 20w50 is that it is a 20w50 oil so can still have a higher ZDDP content as modern automotive engines do not use a 20w50 rated engine oil. That isn't saying that it does have more ZDDP,  just that it 'could have' more ZDDP (I haven't ever been able to find the actual ZDDP content of the newer Castrol GTX 20w50 oil)

 

A number of older-motorcycle riders do seem to use the Castrol GTX 20w50 without issue so it probably won't kill your old BMW boxer but it sure wouldn't be one of my recommended motor oil's to use in your old 1100 boxer bike unless the ZDDP content could be verified.  

 

You would probably be MUCH better off using the (Castrol GO! 4T 20W-50 Conventional Motorcycle Oil) as it still has the API SG rating & is a motorcycle specific conventional motor oil. 

 

Bottom line: would I personally use the Castrol GTX 20w50 in  my old 1100/1150 boxer bikes? -- Probably not unless that was all I could get & I needed oil to continue riding. 

 

I do use the   Castrol GO! 4T 20W-50 (API SG/JASO MA2)   in some of my old 1100/1150 bikes due to the higher ZDDP content & it being a conventional motor oil.

Is the higher ZDDP content really needed in the old BMW boxers??? I don't know, but back in the 1100/1150 era BMW thought so & published a service bulletin stating so.

 

 

 

 

 

 

 

 

[Tush]

I’m assuming that you could use Valvoline VR1 20/50 Conventional oil if you were looking for higher levels of ZDDP.   I use this in most of my Classic Sports Cars.  
 

Cheers

Tush

[dave_a]

I add this weasel juice to my Walmart Mobil 1 15w-50 in my R1100R and my 69 Jag.

I calculated a couple ounces will get the zddp level to the 2000 range which is my personal scientific wild ass guess (SWAG) happy range.

Less money than buying the "right" premium oil. My rationale is it allows me to change oil more frequently and I can get M1 down the block Absolutely no scientific proof that any of this will work

One observation: No exhaust valve guide seals on the 6 cyl. and there's a good puff of smoke on a hot restart. More so than with conventional oil.

I can guess oil usage may go up as was said earlier. 

 

[SmokinRZ]

Good morning everyone,

 

Thank you for all of the replies.  I just drained the last of my VR1 20/50 stash I had left over from my air cooled Porsche 911.  I was hoping to replace it with something more readily available and I wasn't sure how robust the detergent package is in a racing oil.

 

I found an oil analysis from blackstone labs for Castrol GTX 20/50 that reported zinc at 944 and phosphorus at 946.  I also found more than one reply from Castrol that GTX was not recommended for flat tappet lifter.  This makes me wonder who exactly is their target market is as any modern roller motor would use a lighter oil.   

 

I'm going to run up to Pep Boys and see if they have some Castrol 4T 20/50 in stock, and if they don't I might pick up some Mobil 1 15/50.  I was hesitant to use the Mobil 1 since there were reports on the 911 forums of leaks after switching over (similar air-cooled boxer motors made in Germany).  I know Mobil 1 is not a true synthetic, but my bike is a 98 with 54K miles, so why take chance.  Plus I like to change my oil more frequently.

 

Another though was to use Rotella 15/40.  I used it one winter when I first got the bike as a short interval flush, plus it was winter.  With the advances in oils over the past 20 years, I wonder if the 50 weight requirement for temperatures over 85 degrees is outdated.  I live in Texas where it gets hot as hell so I like the idea of 50 weight oil.               

 

              

[dirtrider]

34 minutes ago, SmokinRZ said:

Good morning everyone,

 

Thank you for all of the replies.  I just drained the last of my VR1 20/50 stash I had left over from my air cooled Porsche 911.  I was hoping to replace it with something more readily available and I wasn't sure how robust the detergent package is in a racing oil.

 

I found an oil analysis from blackstone labs for Castrol GTX 20/50 that reported zinc at 944 and phosphorus at 946.  I also found more than one reply from Castrol that GTX was not recommended for flat tappet lifter.  This makes me wonder who exactly is their target market is as any modern roller motor would use a lighter oil.   

 

I'm going to run up to Pep Boys and see if they have some Castrol 4T 20/50 in stock, and if they don't I might pick up some Mobil 1 15/50.  I was hesitant to use the Mobil 1 since there were reports on the 911 forums of leaks after switching over (similar air-cooled boxer motors made in Germany).  I know Mobil 1 is not a true synthetic, but my bike is a 98 with 54K miles, so why take chance.  Plus I like to change my oil more frequently.

 

Another though was to use Rotella 15/40.  I used it one winter when I first got the bike as a short interval flush, plus it was winter.  With the advances in oils over the past 20 years, I wonder if the 50 weight requirement for temperatures over 85 degrees is outdated.  I live in Texas where it gets hot as hell so I like the idea of 50 weight oil.               

 

              

 

Morning SmokinRZ

 

The Castrol 4T 20/50 is probably the best bet as far a conventional high ZDDP oil that still has a decent amount of seal conditioner in it. I have run that oil for years in some of my older bikes & it is based on a pretty solid base stock so I really don't see much long term shearing even with all the chains spinning inside the old BMW boxers. It has always tested good from Blackstone for me so why try something else. 

 

The Rotella 15w40 is still a pretty decent motor oil (great heavy duty tractor oil)  but will probably be a bit on the light side in real hot ambient temps after it shears down a little. (won't hurt your engine but will probably be a bit noisier in hot weather). 

 

The Mobil 1 15w50 is also a good oil, protection wise, but it doesn't contain a lot of seal conditioner so you might end up with some oil seepage after is has been run in for a while. (some 1100/1150's do great with it & others do seep a little).

 

If you already have the Castrol GTX 20/50 just dump that in then order some Castrol 4T 20/50 on-line (maybe try Amazon with Prime free shipping). Amazon will usually give you a free prime membership for a month then you can cancel  with no membership charge.  The Castrol GTX 20/50won't ruin your engine, just probably not something that you want to run  full vehicle life. Won't even have to change the oil filter as the  Castrol 4T will mix easily with the little bit of  GTX left in the engine.  

 

 

 

[SmokinRZ]

Thank you DR,  your opinion is greatly appreciated.  I went by the local Pep Boys and got some Castol 4T 20/50.  I can run the GTX in the lawn mower and other low level machinery.     

[SAS]

Castrol 4T 20W-50 the only way to go, for the older rigs.  Been running this stuff for a long time and never had any adverse reactions.