Alrighty then. Thanks. There is nothing I can do about lowering my ping under 180ms to 200ms - that means it's getting there as fast as it can, but I was at least I was able to lower it from 600+ms, which counts as a win for me, thanks to the help here. Luckily my internet is stable most of the time, this must be the reason I've been fully able to enjoy racing rFactor 1 online for a while. Regardless of spikes causing latency issues due to high CPU occupancy, I have always lowered my settings to a more medium level, so that will never be a problem. I hate racing when the FPS is anything under 60.
So it seems that the "New Prediction Algorithm" value that was added to build 382 seems to be a culprit in many cases for bad online behaviour, especially for any pings higher than 100ms. Disabling it in the Multiplayer.ini file seems to be resolving most people's troubles. 2 leagues I know of, have already made it a requirement for this setting to be turned off by its players in order for them to be allowed to participate. Maybe it should be refined a bit more first before we try it again.
I was also reported about jumping cars (which seemed lag in a video) in our league race yesterday. Everyone who had algorithm as 1 had this problem and we who had it at 0 didn't have that problem. So I can confirm this too.