Originally Posted by 13WaysToBleed
From what I understand there are many synthetic oils out there that are better than Mobil 1 for around the same price or a little higher. I'm not sure on this but I heard that Mobil 1 is only a Group III oil. While Group III is considered synthetic, only Group IV is true synthetic and is the superior oil. I think at one point Mobile 1 was a Group IV and that's how they earned their rep. Regardless, do a little research you'll find a better oil.
Here's a chart from Amsoil. Granted it is Amsoil promoting their oil so take it with a grain of salt.
It should also be noted that Amsoil and Castrol are 0W30 not 5w30