Hello all. It has been brought to my attention that we are supposed to use 5w-40 oil in our machines. I have been using 10w40 motul 7100 for 20,000 miles and it seems to run fine. I also ride every day through traffic in an extremely hot climate. Should I make the switch to 5w oil? It just seems like it would be a little too thin for the Texas heat. Any opinions or inputs are welcomed.
Thanks. I think I'll switch over to 5 weight oil after my bun burner run next month. Im on a 07 k12gt and my manual recommends 10w-40. I guess BMW figured lighter oil is better for clutch lubrication? I just replaced my clutch for the first time last weekend anyways, so I assume I'm good for another 5-6000 miles on fresh 10w40.
My feeling is, if there is no problem with what you are using now, why change it? I had this same question with my K1200R Sport last week and posed it to Dirtrider on bmwsporttouring.com .
If you would like to see the response that I received (he is extremely knowledgable), check it out here:
only caveat is its dependant on the use and conditions… if you do lots of stop start riding in less than 30C temps (90F or whatever it is) then the 5w will help.
If you do long runs, riding hard in hot temps, use oil at the other end of recco range
BMW changed the oil recommendation from 10w 40 to 5w 40 in an attempt to solve the oil feed problem to the clutch and it’s resultant problems
My 2008 manual still shows 10w 40 however.
In a 5w-40 for example the 5w bit (W = winter, not weight or watt or anything else for that matter) simply means that the oil must have a certain maximum viscosity/flow at low temperature. The lower the "W" number the better the oil's cold temperature/cold start performance.
5 stands for oil viscosity at 0 degrees C, W stands for Winter, 40 stands for oil viscosity at 100 degrees C, that is the oil thickens as it get warmer.
That’s correct and why BMW changed to 5w 40 so that the clutch would receive oil quicker on start up. The manual also states that 15w 40 is acceptable in warmer temperatures.
The change in spec from 10/40 to 5/40 was done by BM in 2010/11 the problem then being the cam chain tensioner wouldn’t hold the oil with it being thinner and you got the death rattle at start up hence the the cam tensioner recall and replacement.
the change in spec from 10/40 to 5/40 was done by bm in 2010/11 the problem then being the cam chain tensioner wouldn’t hold the oil with it being thinner and you got the death rattle at start up hence the the cam tensioner recall and replacement.
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