Flethca, do you notice any buriong oil smell to loss of oil when you drain the 5w 30??? Im thinking that the only reason you would get less power is if you had bad rings and you were getting blow-by....Because when i went form 15w 30 to 5w 30 i got better performance.....or maybe Mobil one set a mis- labeled batch of oil to your location....lol....just kiddin...but hey, if you car gets a clean bill of health, then it would be intresting to see....Can i reconmend a Dyno of each oils then post them....amybe that can help clear things up.
Roz
