Here is a link to teach you more than you would ever want to know about motor oil. Motor Oil 101 - Bob is the Oil Guy - Bob is the Oil Guy

 

The NOACK percentage is why I say Pennzoil conventional matches up favorably to most synthetics. Also the high tbn number and amount of moly and boron additives it contains. Once again though any oil that meets SN GF-5 is a good oil but when it is actually cheaper than most synthetics or blends why not use an oil that has the better specs? If you read on the oil section of this site, member PawPaw often posts good links and is extremely knowledgeable about oil.