As the year comes to a close and temperature drops, we in the northern climes must put our bikes away for the long, cold winter. Here are a few tips on what to do to keep your bike in top shape: Change the oil & filter first (rather than keep the shmutzik oil and particles in your bike, over the winter), fill the gas tank (even though I only use regular, I'll put in 92 octane because it will lose some power and importantly 'fuel stabilizer' which minimizes the loss of fuel quality over the long period). You should add the stabilizer with your last fill up, run the engine for ten minutes before shutting down, for the season. You want the tank full, so there's less air inside (which causes oxidation -- rust).
The bike should be cleaned before being covered. Any insect splatter or bird poop (acid) destroys the paint. Once clean, apply a coat of wax, then cover.
If you have a center stand, use it. Place a couple of pieces of styrofoam between the tires and the concrete. Ensure they are properly inflated as air will leak out during the winter. Ride only with the proper air pressure for maximum tire longevity (and safety). Check the pressure, at least, weekly. Lastly, either remove the battery or connect a battery tender to it (an automatic charger) so that months later, your baby will start like new!
First thing is that all manufacturers are legally responsible for "use as intended". Motorcycle oil from a well-established motorcycle oil supplier/manufacturer usually has a good reputation and the manufacturer stands behind his product. All "big engine oil manufacturers" test their oils on the engines they advertise to protect and in their intended use evironment. But note they stand behind "use as intended" only. If someone decides to play chemical engineer, he can, totally at his own risk; his engine life will shorten most likely, by how, it depends.
That said, all brands have their own secret recipes, some will "work better" with some engines, and not as well with others. You'll know by the clatter the engine makes. That is about the only kind of "experimentation" that makes sense.
Synthetic oils simply last longer and are more slipperier than mineral oil. They also provide a better "metallic bump/shock" cushion. Mineral oils are best used to break-in a new engine (at low rpm) - are little less slippery, are a little quicker wear so that parts will wear into each other before they get carbon-coated. Recommend oil + filter change at 300 miles then again at 1000 miles but switch to synthetic at 1000 miles.
You know your bike best because you ride it and have a feel for it. After trying many brands of motorcycle oil, I settled on using Yamalube Gold synthetic because it results in the least engine clatter on my super blackbird. I can sense the bike is happy. Yes it's a tad more expensive, but i don't blow my money on frivolous things, I spend my money on stuff that matters to me. My super blackbird is a 2002 and it runs like new. Guess why.
Example of what can go wrong:
A diesel engine is purposely built to be under load (hauling, etc...) at low RPM for hours. To survive, diesel engines are built to exact specs/tolerances, lots of metal, big bearings, etc... expensive but built to work hard. Diesels burn diesel fuel, it's dirty, leaves behind a lot of carbon and by-products Gasoline engines do not work as hard, used in cars and bikes and are used to accelerate for a short time and then coast. If a gasoline engine is used hard, it won't last. Gasoline is a pretty good solvent and on long trips, tends to dissolve a lot of carbon into the oil.
Diesel oils are specially formulated (with carbon dissolving detergents) to clean out diesel engines because because they get dirty. If you use a diesel motor oil or do a "super flush" of an older (or even a newer) gasoline engine you will regret it. Gas engines will have "micro cracks" that fill with hard-to-dissolve carbon and help seal the engine. The high-powered detergents will dissolve those beneficial carbon fills and engine will not be sealed any more. Exhaust blow-by, etc... problems will spring up. Why? Because someone played chemist?
The chemists that develop engine oils are keenly aware of all of the above and much more. They develop their products for specific engines, the fuel they use, and the way the engines are used.
Use oil for intended use! Use good quality oil if you want zero problems, preferably synthetic.
Ride safe,
all the best,
Yani.