I have a BMW F750 GS and I’m driving through Colombia now and I’m planning to ride through whole South America. I’m not technical at all. I’m reading a lot and did a maintenance course before I left, but didn’t understand what the teacher was talking about most of the time.

In the north of Colombia I needed to fill the oil. In the manual it is advised to use Advantec Ultimate oil, SAE 5W-40, API SL/ JASO MA2. In the north it is very hot and they only had 20W or higher. I didn’t know what oil was in the motorcycle because I bought it second hand. I read on the internet that mixing oil is not always ideal, so a few weeks later I had the oil replaced by JASO MA2 10W- 40 semi – synthetic, because they didn’t have 5W-40. From what I read fully synthetic is the best.

Now my questions
Would you keep looking for 5W-40 fully synthetic oil and change the oil for the best type, or would you just ride on with the one I now have?

I understand that 5W-40 fully synthetic oil is the best, but I don’t know if it is really worth the effort to change the oil. I don’t mind if my motorcycle is not running perfect, but I don’t want real damage on the long run.

Another question: I can imagine that if I’m in another place they don’t have the oil that is now in my bike and I will mix oils again. Would you replace the oil again instead of mixing it?

Thanks a lot!

I mix oil weights, ratings and brands routinely without worry or apparent consequence--car, truck, motorbike, lawn mower, you name it. Every vehicle I've ever owned has insisted that only their special house brand of oil should be used, but I've never paid any attention.

Take that as one data point.

Mark

Thanks a lot!

I would try to get as close as you can to what should be in there but not lose any sleep over it. Any of the oils you're likely to find will physically mix with each other so its not going to be like mixing oil and water. I'd be amazed if you - or the bike - could tell the difference between 5W-40 and 10W-40 other than by what's on the label. I certainly wouldn't change it until the normal interval had passed.

The bit at the end of the spec, where it says JASO MA2, that's about whether it will cause your clutch to slip. MA2 marked oil is supposed to make sure that doesn't happen. Again, like everything on the internet, some people say it's important, other say it isn't.

This is one of those "technically true but in practice, not always useful" things. Fully synthetic oil stands up to the most abuse in very high-performance engines, but the engine on a mid-range, long-distance, partially offroad-focused bike might be built to take advantage of a semi-synthetic oil's particular performance in particular circumstances. So in general, use the oil that the manual tells you to use.

Given that you'll be at least a few thousand kilometers in before you have a chance of finding the recommended oil, I think it's entirely justifiable to get it replaced at that point. Since you'll presumably be doing it at a capable motorcycle mechanic shop (rather than yourself - which is easy enough to do, but sounds like you're not inclined to do that), take it as an opportunity to have the shop go through the rest of the bike, inspect it thoroughly and tell you if you need to replace anything else for the rest of your trip. Chain, bearings, brake fluid and pads, coolant, clutch and throttle cables, etc...

If you've got the full quantity of new oil available (and a new filter), I can't see a meaningful downside in just replacing it fully. I'd only mix oils if I can see that my oil level is low, and I'm out in the wild somewhere - in such circumstances I've certainly topped up with the closest available four-stroke motorcycle oil from the gas station, under the principle that mismatched oil is better than no oil.

Mineral and synthetic oil mix readily. Old generation vegetable (castor) oil does not mix with them, but you won't generally find that these days anyway. Obviously synthetic (or semi) is best for lubrication, particularly in hot conditions but if you need to top it up you can use mineral - better than letting it get low. Try and keep to recommended oil and filter change intervals (oil does get contaminated and degraded) and *if possible* use semi or full synthetic oil. The preferred grade for hot weather would be xW-40 or xW-50.

Since your engine is liquid cooled, it wont really matter much what oil grade you use. 5w-30 is the best, but anything will work just fine.

For air cooled engines you should use 50w oil in hot temps.

Any oil is better than no oil.


Just go for the best you can get. Forget the W number. It's just the winter rating. You won't be worrying about that in South America.

You can safely use 40 or 50 on your bike. 30 will work but I think it's too thin.

MA1 (or just MA) is fine with yours too. (MA2 is the new standard for wet clutches). But it didn't exist when your bike was first designed.


Instead of endlessly mixing oil just change the lot with the best you can get.

But it MUST have an MA rating . Don't use car oil.

__________________
Did some trips.
Rode some bikes.
Fix them for a living.
Can't say anymore.