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15W-50 instead of 10W-40?

OIL THREAD!

Will the sun fall from the sky if I use 15W-50 in my K1600GTL? I have couple gallons left from my RT.
 
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I have serious doubts, the engine will recognize the difference. Depending on where you live and what temperatures you ride in, the 15-50 may actually be a better choice (high temp advantage). I use 20W50 in all my bikes except my old HD shovelhead sidecar rig, which only gets 60W.
 
Warranty

Ask the BMW dealer-

You will Void your Warranty!!!:banghead


All dealers have a viscosity checker if you use the incorrect weight oil they will know right away.:dance

Believe it!!!

It's your bike you need to do what is best should not hurt the engine.
 
What a drag

I agree that it should not hurt the engine, but they specify a certain weight for a reason. At the least, the engine (or at least the oil) will run a bit hotter, and there will be a very slight decrease in fuel mileage.

Heavier oil is thicker... thicker oil increases friction... friction = heat and drag... heat and drag reduce mileage.

You may not even notice it, but it will be there. Personally, I'd sell the oil to a buddy who needs that weight, and use what the factory recommends. However, it's your bike...
 
liquid cooled engines generally use lighter oil. They have tighter clearances.

The flow rate of 15W50 is lower, this can cause bearings to overheat, also reduces and delays the flow of oil to the heads.

Get the right oil. Odds are it would be fine but risking warranty on a new EXPENSIVE motorcycle over some leftover oil, I would not do it.

Rod
 
Owners Manual

The owners manual also specifies 10w-50 weight oil. I'd use it in summer months, if I could find a supply. The problem is that it is expensive. The BMW brand 5w-40 is a whole lot cheaper than other 10w-50 and BMW doesn't make 10w-50 motorcycle oil.
 
BMW doesn't "make" any engine oil.

And, the USA is the only place it sells BMW-labeled oil.

In the rest of the world, BMW recommends Castrol.

Here's the chart: http://www.bmw-motorrad.co.uk/media/pdf/70583_A1_BMW_POSTER_MCO00066_low_res.pdf

The six isn't there yet, but I'd guess the recommendation is same as S1000RR, K1300, etc., i.e. Power 1 Racing 5W-40. The USA version of this oil is called Power RS Racing: http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9040397&contentId=7040544
 
Every vehicle owners manual I've ever looked at has an oil weight vs. temperature chart.

I think you mean "oil viscosity vs. temperature."

The numbers 0, 5, 10, 15 and 25 are suffixed with the letter W, designating their "winter" (not "weight") or cold-start viscosity, at lower temperature.
 
Oil viscosity

I believe the first number in a multigrade oil is an indication of viscosity grade (weight - not winter) of the base oil without the viscosity improvers (VI). The second number is the resultant weight with the VI additives. Multigrade oils with VI additives maintain a more consistant viscosity as the temperature of the oil changes. Modern engines are designed with bearing clearances and cam/follower profiles that require the multigrade oils. The synthetics also retain a flatter viscosity vs oil temperature and they don't break down as rapidly. However, they still get dirty just as fast and they are just as susceptable to fuel dilution as non-synthetics. I just had a used oil sample from by GTL (5w40 synthetic) analyzed after 5000 miles and the viscosity had dropped from 14.5 to 10.4 due to fuel dilution. Time for an oil change.
 
All dealers have a viscosity checker if you use the incorrect weight oil they will know right away.:dance

Believe it!!!

I gotta call BS on that one. 25 years in car dealership shops and I've never even heard mention of a viscosity checker, let alone used one. :scratch
 
All dealers have a viscosity checker if you use the incorrect weight oil they will know right away.:dance

Believe it!!!

I'm pretty sure that all bikes produced after 1500 hours, Central European Time on June 12, 2008 have a SAT based transponder onboard that will transmit the weight of oil you are using directly to the OPS Zenter at the mother company's HQ in Stugart. If you use the improper oil they will send a Telex informing you that your warranty "ist kaput". The system also detects oil levels that fall .001 microns below dead-center in the window, tires that are more than .25 PSI over or under the BMW directed pressures and the condition of your final drive. This later function allows BMW Zentral to send you a letter denying your warranty claim for the FD and blaming the failure on your use of poor fuel and improper braking techniques. It is not uncommon for these letters to reach an owner before he/she is even aware of a FD issue. Believe that!!! :p
 
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