Oil grade

[sockets]

BMW recommends Castrol power 1 racing 5W-40 and 10W-50.

Cant get a 4litre can of 5W-40 anywhere but there is alot of 10W-40 about and some 10W-50.

Anyone know what the dealers use?

Cheers.

 

[RossHarper]

Dealers use 5-40 castrol because of the deal between BMW and Castrol.

I've tried many oils, now using 15-50w semi (I do a lot of short hops on bike, so sometimes oil never warms up). Was running fully synth but engine sounded tinny and when I dropped it after less than 3000 miles the oil was like water (Silkolene)

Any semi 10-40w would be fine. If you have the CAT still then use a JASO MA-2 rated oil, however if CAT is removed (full exhaust system) then use a JASO MA oil. MA-2 oil is circa 06 when bikes started coming with CATS, it has less of the protective minerals in it because these were found to damage CATS. If you have no CAT then MA oil will protect engine better.

 

[alex]

My choice would be a Ester based oil. Fuchs Silkolene Pro stuff... Opie Oils will give you the best option if you call them. They are on here so I would assume there is a club discount...

I *think* 5w or 10w would be decided by what sort of riding you do and the mileage of the engine. 5w is thinner and good for short journeys as it gets to the places it needs to get faster than 10w. But 10w is better for long journeys... (beyond nipping to the shops). This is all what I think, so I'd check that with an expert. The 2nd number is a relative number to explain resistance to shear and breakdown I believe... so I'd go for a higher number quite happily.

 

[sockets]

Thank to both Ross and Alex.

I have full Akro on mine(no cat) and have now done just short of 18K.

I guess I am looking for 10W-40 JASO MA - is that out there?

 

[RossHarper]

Yes, use opie oils, they let you search by oil spec rather than just grade.

Also 10w-40 is the viscosity of the oil at different temps.

10w (W = winter) when oil is cold it meets a 10w oil viscosity.
then 40 is when oil is at 100 degrees. Means it's much thicker.

Oil also loses it's viscosity over time, after 1500 miles it can be down by 20% in viscosity, so starting with a 5w, I would do much short distance between oil changes.

I have read somewhere that thinner oils like 5w can give slight bhp increases, so perhaps thats why BMW recommend it.

 

[sockets]

Top info - thanks Ross

 

[apetrov1x5]

can one use 15W-50 fully synthetic Mobil One racing? I have a canister from the previous bike and if it is good for S1K, I will use it (would hate to through it away)