- Joined
- Jun 3, 2021
- Messages
- 832
This is why I'll never use a diesel oil in a motorcycle, and I think the myth that diesel oils are the superior option for all applications really needs to stop. There are riders that run Rotella in motorcycle engines that redline at 14,000 RPM instead of 4,000. To me, it's like you said - you're running that oil outside of the parameters in which it was designed to be adequate for.There's nothing special about a CK-4 oil, especially for racing use. They tend to be volatile and lacking in friction reducing additives which is the opposite for what you want for a racing oil. You want low volatility so the oil doesn't evaporate as much around the rings and can hold a better, thicker oil film. You want a lot of friction modifier to drop the CoF for less friction and more power. You want minimal VII loading to ensure the oil is shear stable. There's no CK-4 oil on the shelf at Walmart that caters to that environment. An oil formulated for a diesel engine turning 4000 rpm max with a big oil capacity measured in gallons isn't going to be favorable to a gas engine turning twice that rpm with half (or less) the oil capacity. They're two very different environments that like distinctly different formulas.
Are motorcycle specific oils, or in your case, racing specific PCMOs a bit more costly than picking up Rotella at Walmart? Yeah. But what does that small savings cost your engine if that Rotella becomes frothy? It's like people think that because diesel engines are "tough" that the oil they spec must also be automatically more resilient across the board.