Just use a name brand synthetic and I change mine at 5 to 6K miles. I can't buy into a 10K interval unless it were a lease car which mine isn't. The main thing is keep it changed. Oils are so good today it almost doesn't matter which one you use. The Motul's of the world are good but not worth the price on an economy car engine that doesn't work hard. I've driven my R18 at over 100 for over 2 hours once to make up time and it wasn't working hard to do it at all. On high revving motorcycles, it's a different story. FWIW.