Shell Rotella T6 Full Synthetic 15W-40 Diesel Engine Oil, 1 Gallon

Motorcycle is a Honda ST1300 with 13000 miles on it. Have used the Rotella Synthetic, ostensibly advertised for diesel engines, but without the "high efficiency" additives, it works very well with my motorcycle. Clutch is just as good as new, and the engine uses no oil. To boot, the container has four quarts in it, and that just fills the ST. The Amsoil salesman stated that there is now no zirconium in Rotella T synthetic, but in my opinion there is a limit to the addition of trace elements to motor oil, and since the synthetic is a superior lubricant that will not carmelize, it is plenty adequate for everything except maybe flat out racing.

And if you take advantage of the oils ability to take care of your engine for extended oil change periods, it is the most economical. Buy oil filters designed specifically for synthetic oil and extended oil change periods and you can safely change oil every 10,000 miles. If you install a bypass oil filter in addition to your regular spin on filter you can extend your oil change periods even further. On my truck and car I change the element in my bypass filter every 5000 miles. I change my spin on filter every 10,000 miles. I also send a small sample of my oil to an oil testing lab at regular intervals to determine if I need to change oil and to determine the health of my engine. I have purposely not endorsed any products other than this oil so you can do your own research.