What is the difference between TC-W3 and Full Synthetic? I assume full synthetic will bring out the best performance in my waverunner. Is it ok to switch my waverunner from Pennzoil TC-W3 to Pennzoil Full Synthetic? I am running the stock engine, no performance parts at all. I just want whats best for the waverunner, as far as performance and no gunking up in the engine. Thanks