oil change: 10-w-50?

[sstein]

Did an oil and filter change today after a nice first-ride-of-the-season.

I had ordered Liqui-Moly synth 10W50 racing oil since that looked like one of the top choices on Beemer Boneyard for the R1150R.

Later was reading through the Clymer manual and there is a chart that shows that 10W50 is recommended up to like 50 degrees or so, and 20W50 is preferred for higher outdoor temps.

Is that a problem? Bike is 02 with 27K miles. I am in the NE where summer gets up to mid 90s often.

Should I change the oil? Don't want to damage the engine.

Thanks,
Steve

[sstein]

Never mind. I called beemer boneyard customr service who told me that it is fine and not to worry about it.

[towerworker]

You're probably fine. When you ask about oil on this forum be prepared for all sorts and types of opinions! I've put about 100K on R's so far and I've always run Castrol 10w40 in winter and 20w50 in summer. Straight dino oil, not synthetic. I change every 3K and have had 0 (zero) engine difficulties. If I lived out west or subjected my bike to a lot of city stop and go traffic and extended idling time I'd run synthetic. But I live in the best place in the country for motorcycles so I'm good! Just run the heck out of it and have fun!

[peels]

20w50 wont hurt a thing I dont believe. And, it'll be better the hotter it is and the harder you ride. that is MY opinion, though. agree with tower above^ Starting oil discussion is one of the most nauseating things you can do on a machine forum. People get angry- its weird.

[towerworker]

The very back cover on my BMW Maintenance guide says "BMW recommends Castrol". (2003 & 2004)

On the oil vs temp page (page 3/74) it says 20w50.. 20-90+ degrees F. 10w40 from -5 degrees to 70 degrees F. The same Castrol oil recommendation is on the bottom of the opposite page.

[CycleRob]

sstein,
Keep and go with the premium synthetic oil you have in it. Synthetic oil has superior boundary film lubricity (the MANY places where parts move against each other without any oil pump pressure) at very high temperatures your OilHead is likely to see in summer traffic situations. It is so good that you should NOT use synthetic oil until the engine has been run enough to "break it in", which can be 2,000 to 18,000+ miles on an OilHead, depending on how hard it its ridden. The premium chrome steel piston rings and cast iron cylinder liners of the OilHead motor almost require a race track to break them in to reduce the required 2 or 3 oil additions before the oil is changed at 6,000 miles. I did not have a race track, but riding the deserted, steep, mountain roads in up-state New York with 2 "capable" CECS racer friends on their street sportbikes one Sunday FINALLY did the trick . . . at about 18,000 miles! No more oil additions needed after that.

About the viscosity numbers, the lower 10W designation means the oil is thinner than the 20W oil ONLY at -30 degC (−22 degF) and the "50" identifies the viscosity at 100 degC (210 degF). The benefit in a warmer climate cold start is that the 5W-50 and 10W-50 oils will circulate slightly easier/faster during a cold engine start than the 20W-50 oil will. The more important number to worry about is the second number in which the engine manufacturer's specification should be followed. Many new cars require 0W-20 oil! The engine bearings and many other parts are designed for 20 weight oil at full operating temp even in summer.

Below are some links to oil "experts" with serious technical explanations about what those numbers mean. Most relevant is this: "The measurement temperature used depends upon the W-grade. For example, SAE 5W grade oils must be evaluated at -35 degrees Celsius (C.), while an SAE 10W grade oil must meet J300 limits at -30 degrees C."

http://www.upmpg.com/tech_articles/motoroil_viscosity/

Explaining the oil classifications (PDF file download):
http://www.api.org/~/media/Files/Oil-an ... .pdf?la=en

Popular Mechanics Oil tutorial:
http://www.popularmechanics.com/cars/ho ... 3/1266801/

Another from these guys:
http://www.sae.org/news/releases/rightoil.htm