This from an Accord forum I frequent:
Originally Posted By: ;796896
If it were my car I wouldn't be running that.
Castrol (as well as Valvoline) has had a recent history of not passing all of the specs they claim to "exceed".
Based on their product data sheets, the oil is slightly thicker than other brands at both hot and cold, and the colder it gets the thicker it is. Their 5w20 is actually much thicker at very, very cold temps than their 5w30.
It could be draining out of the vtc actuator more easily. It could be as simple as that. or not.
I'd be looking at the following oils:
Shell and their sister brands, Pennzoil and Quaker State. (both are owned by Shell)
The Shell oil is usually less expensive, but just as good.
Motorcraft Semi Syn 5w20 and other ConocoPhillips oils. It seems now that's who makes MC oil, as well as Honda's US factory fill and dealer oil.