Syn 3 vs Mobil 1 V Twin
I have been using Mobil 1 V Twin, for just over a year. I also use Spectro 6 Speed in Transmission, The Primary has Syn 3 and I have no clutch slippage or any other problem. It all worked great and I never add oil between oil changes, (every 4,000 miles). When I got the 10K service from HD dealer he put Syn 3 in all three holes. I took bike home and drained out the Transmission and saved the new Syn 3. Then put in the Spectro 6 speed. I had noticed when I first bought the bike after the first 1500 mile break-in, that on long runs the dealer supplied Syn 3 oil tended to foam a little. Not enough to leak out the top but if I pulled over and checked oil level after running there was enough foam in the pipe that it was hard to tell where the foam stopped and the actual oil level. I also had to add a little every 2000 miles. Once I switched to Mobil 1 V Twin I had no foam in the pipe and never had to add oil. Now I just run with the Syn 3 and yes the foam is back, but I have some extra Syn 3, saved from the Tran to top it off with, until my next oil change when I will return to Mobil 1 V Twin.