what you need to remember is they take emision control into consideration. with that said their recomendation might not be for peak performance.

 

I'm with him....Royal Purple,Amsol and Mobil 1 in that order.

 

Check out how Quaker State's backs up it's oil.

 

Factory semi-synthetic, factory suggested drain intervals - you can't go wrong. Anything else just increases your cost of ownership. I am guilty of falling for the synthetics in the past, I did run mobil 1 in my last car on 10k drain intervals even with an 11.5:1 compression ratio, an 8100 rpm redline and 100 hp per liter :R: The compression was still good as new at 90k on that car though. The tech was amazed but not surprised, he had just seen the same model car with 130k miles that used factory oil changed at 10k and it was no different...to each his own but what it all boils down to is there is no right or wrong choice here.