20w50

[Cheesy Mike]

So did mine last time they serviced it, but that doesn't mean it's right. It all depends on whether you trust the manufacturer and designer of the engine (see oil viscosity table in the owners manual) or your local dealer.

Now I know the correct grade to use, and since I do my own servicing, the bike'll never get anything as thin as GPS again.

I'm intrigued. Why do you think Castrol GPS is not the right oil for an 1150 oilhead?

Mike

 

[sproggy]

I'm intrigued. Why do you think Castrol GPS is not the right oil for an 1150 oilhead?

As I said previously, have a look at the viscosity/temperature table in the owners manual. I've only recently been made aware of this through the forum but it is stated very clearly had I chosen to read it when I bought the bike.

GPS is 10W-40 which the manual specifies is suitable for ambient temperatures up to 20 degrees celcius. It goes on to warn that you shouldn't operate the bike above the maximum ambient temperature for the grade of oil that you use except very briefly. Most summer days in the UK it is above 20 degrees, and occasionally over 30 degrees, therefore when running the bike with GPS in the summer months you are exceeding the 'safe' ambient temperature for a 10W-40 oil - basically you are putting your engine at risk according to its manufacturer. If you take your bike to Southern Europe in the summer you should expect to experience temperatures around 40 degrees - 20 degrees higher than the recommended limit with 10W-40. 20W-50 is quoted as being suitable for ambient temperatures exceeding 30 degrees celcius and down as far as -10. Below -10 (if you really wanted to ride in those conditions!) you'd need a 15W-50, 10W-50, 15W-40 or whatever - they're all listed with differing temperature ranges.

 

[Cheesy Mike]

As I said previously, have a look at the viscosity/temperature table in the owners manual. I've only recently been made aware of this through the forum but it is stated very clearly had I chosen to read it when I bought the bike.

GPS is 10W-40 which the manual specifies is suitable for ambient temperatures up to 20 degrees celcius..... (snip)

Thanks. I didn't know that.

Mike

 

[sproggy]

Thanks. I didn't know that.

Me neither until last week, hence the panic purchase of some thicker oil before my track day

Seems that 'everyone' uses and recommends GPS and no-one reads the manual, and I'm as guilty as the rest. Once you've heard your engine with thicker oil in it (or, rather, not heard it) you won't want to go back to GPS either!

 

[Sea Lion]

Me neither until last week, hence the panic purchase of some thicker oil before my track day

Seems that 'everyone' uses and recommends GPS and no-one reads the manual, and I'm as guilty as the rest. Once you've heard your engine with thicker oil in it (or, rather, not heard it) you won't want to go back to GPS either!

I'll verify that, changed mine and it runs noticably quieter, smoother and slightly cooler for some reason. Due to change the oil again soon. Will probably try some 15w-50 over winter.

 

[Greg Masters]

I'm intrigued. Why do you think Castrol GPS is not the right oil for an 1150 oilhead?

Mike

It is designed for wet-clutch engines and, as such, does not contain friction modifiers that improve the lubrication qualities of the oil.

On top of that, it's fecking expensive!

Greg

 

[Greg Masters]

Will probably try some 15w-50 over winter.

The wider the multigrade range, the shorter the oil life.

Semi-synth and (more so) fully-synth oils withstand high temperatures better than mineral oil.

Greg

 

[Greg Masters]

GPS is 10W-40 which the manual specifies is suitable for ambient temperatures up to 20 degrees celcius.

That's true - but just think about that for a moment.

My bike pretty much runs 5 bars oil temperature whether the ambient is 0 degrees or 30 degrees - ie the engine temperature hardly varies.

The main reason for specing a different grade of oil is to ensure good, quick lubrication on start-up. If the oil in your engine is too thick (when cold) for the ambient temp, don't rev the bollocks off it until the oil is warmed, else you're likely to shag the oil pump etc.

Greg

 

[Deleted Member MM]

There's no 20W-50 listed on that site - nothing heavier than a 15W-40.

I must be seeing things

http://www.havoline.com/products/na/motoroils.html

 

[sjwb]

Let me ask a VERY specific question.
Have you ever seen an oil related engine failure?
Think very carefully before responding.

 

[Le singe]

Yes,plenty,and every one was caused by the owner's believing the oil retailler's advertising rather than the manufacturer of the engine unit.

 

[cookie]

Let me ask a VERY specific question.
Have you ever seen an oil related engine failure?
Think very carefully before responding.

no, except where the owner has failed to put any in.

 

[Le singe]

Why all this debate? My manual states the viscosity required for the ambient temperature,plus the grade of oil,and they're all mineral.
Why not read the instructions and follow them,unless you know better than BMW

 

[Greg Masters]

Why all this debate? My manual states the viscosity required for the ambient temperature,plus the grade of oil,and they're all mineral.
Why not read the instructions and follow them,unless you know better than BMW

It's a fair point!

The weakness in your premise, though, is that oil technology moves on (as does BMW's thinking).

In Nov '98, BMW issued service bulletin No 2855 in which they said not to use API SJ oils in the then current R1100x engine. Later they back-pedalled on that and said that you could use an API SJ oil if the same oil had previously been rated at API SG or SH.

It's all moved on since then. The oil that I'm about to pour into my bike is API SL. It says on the label that it exceeds the requirements of BMW Longlife-98 (now superseded by BMW Longlife-01 and maybe others).

I talked at length with a lovely lady oil guru at Castrol in Swindon. She clearly knew all the technicals (and Howard Godolphin from BMW Bracknell) and couldn't really say why the BMW manual only lists mineral oil.

The problem with the manual for my bike (a 2000 1150) is that it was printed a few years ago and definitively cannot reflect current thinking - whatever that is!

Greg

 

[Big Lad]

http://www.busters-accessories.co.uk/proddetail.asp?prod=SLKCOMP420

Might get some of this. It says 20/50 but the pic is 15/50, but 15/50 seems a pretty good bit of middle ground between 10/40 an 20/50.

 

[Steptoe]

I use morris HD 30

 

[Big Lad]

http://www.morrislubricants.co.uk/

Is it the v-twin stuff ? Can't find HD 30.

OR MOBIL Racing 4T 15W–50
100% synthetic lubricant developed for the highest performance four-stroke motorcycle engines. Its special synthetic base oil and carefully constructed additive treatment is designed to provide both the road and racing driver with the ultimate performance and protection for their machines.
Benefits include the following:-

Fluid to - 51°c and tolerance of sump temperatures reaching upto 160°c.
Very low wear rates and class leading protection from engine deposits.
Elimination of oil induced seizures.
Reduced oil consumption even when used in competitive racing.
Suitable for motorcycles fitted with wet clutches.

AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHGGGGGGGGG !!

 

[damo the onion]

wet clutches. AHHHHHHHHHHHHHHHHH.../QUOTE] Your clutch is dry tho. er....... ;)

 

[FatAl]

Why are people paying out so much for castrol GPS and other motorcycle specific oils? The boxer engine has a seperate gearbox and a dry clutch, just like a car! I've had BMW boxers for years and ran them all on car type oils. I have several friends who run all their bikes on car type oils as well (10/40 semi-synthetic) many of these bikes have the usual combined wet clutch and gearbox. I have read that if using very thin oil such as 05/40, 10/30, 0/40 etc; these may contain 'Friction Modifiers' that can cause clutch slip. Before I started to use Rock Oil 20/50 semi-synth in my BMW's and harley, I used Ford's own brand 'Motorcraft' 20/50 mineral oil, it cost about six quid a gallon and was quite a high spec, something like SH/CG. My local auto electrician shop sells Vauxhalls own brand 10/40 semi-synth car oil for about a tenner a gallon, and I know a guy who has used this stuff for years in his CBR600 and Suzuki750 racing bikes. I think there is an awful lot of marketing hype being used to get people to fork out unneccessary ridiculous amounts of money on fancy engine oil. I buy in bulk and sell on to friends and neighbours, get together with a few mates and do the same, you'd be surprised how much you can save.

 

[Le singe]

I use mineral grade engine oil because it works,I change it twice as often as recommended. That's all that is needed.
Yes,technology moves on,but the engine is still the same, the first oilhead engines didn't suffer failures while they waited for oil technology to catch up!
These engines aren't exactly at the cutting-edge of development!
I used to use Motorcraft oil when in England,Ford told me it's re-badged Texaco Havoline, Ford haven't got their own refinery!