The only problem is that the redline is over $11 per quart. That's my issue with Amsoil as well, I know it is good oil, but I am going to change it often regardless of how long I could theoretically run it. By the time I flushed my engine with redline and then ran the stuff for a sample it would cost me quite a bit of money. There's an old saying" wear a ten dollar helmet if you have a ten dollar head" Pretty much the same with oil. Why in the world would anyone spend thousands on a highly engineered engine that turns over 11,000 RPMs, holds one quart of oil and not use the best oil possible? This is why I NEVER buy used motorcycles.