bump.
nearly service time n this thread wuz buried deep

 

I haven't confirmed this, but the reason I've heard you can not switch back to normal oil after you've used synth for a long period of time is, the synth oil does some thing to the engine gaskets. When you switch back to dino oil, after a while, you're gaskets will be shot. Not sure if it's true it not but that's exactly what happened to the head gaskets in my camaro.

 

The gaskets don’t know if there is synth oil or not so switching from synth to dino oilis not a problem. Going the other way could cause dino oil deposits to come loose, if that is good or not depends where the deposits are located. In some case the deposits can reduce oil leaks from a defective gasket. Normally, you can go back and forth between the two oil types without problem. The choice of dino or synth mostly depends if the engine is runned to the extreme and over a large temperature range. If the temperature range is wide and the engine is loaded to its maximum, the synth oil is the better choice.

 

That used to be true back in the day when gaskets where made of who knows what, the change would make them leak, it doesn't apply anymore.

 

Synth oil works better thanmineral oil only at hightemperature some mineral oils are better to reduce engine noises were synth don't.

 

Synthetics have low foaming. Foaming while not good for the engine does reduce noise. I chop and change from synthetic to dino all the time depending on what is on special. Mostly its synthetic, but sometimes my cheap source isn't available and I get dino. With the low intervals the bike doesnt really care which I use.

 

I use Amsoil and when my bike was hitting the "H" mark on the temp gauge (the coolant overflow tank line blew), it gave me some confidence knowing I had an oil that handled high temps much better than dino.

 

Ive switched to Motul 5100 esther based semi-synth and the bike is running fine after living on dino all its life but then again it only has 8500 miles up.