I have run full synthetic Triumph oil in ever America, SM and Bonny series bikes I have had..I always changed at 3000 miles. I have a new Scrambler that I now run semi-synthetic oil in (Triumph). In fact I changed it at 600 miles and again today at 3000 miles and it was pretty dirty. I do have to say that this is the smoothest shifting, smoothest running and gets the best mileage I have ever gotten of the various bike I have had of the new twin line. I will stay with semi-synthetic from now on and I will always change at 3000 miles. I have been running a pretty steady 50 mpg with an occasional increase to 52-53 mpg and I do ride pretty hard in the upper rev range most of the time.
I for one, do not see any benefit to full synthetic.
