it takes about 1.2 quarts to fill up with oil. Most are using 10/40 weight oil as I do. I stayed with regular dino (Valoline) oil till 1800 miles before switching to synthetic (Mobil 4T 10/40 racing). Others have switched earlier w/o any reported problems. YES use ONLY oil that is good for wet clutch or you will have clutch slippage.