The OCI is 5k miles (8k kms). My 07, Ive used 0w20, 5w20, 5w30, 5w40, 5w50. This engine will take whatever you give it. Ive alsorun conventional but mainly syn since like many of us, I seek out deals. A solid price for oil combined with mail in rebate comes out to the same or cheaper than conventional. Worst case a 5qt of Supertech syn can be had for 16$ or so. That price to me makes it a no brainer. Ive run my oil to 6200 miles using a syn oil and cheapo napa proselect and my oil analysis was excellent, could of gone longer. If I were you, run 6k miles and use the cheapest syn you can find. Even if u choose to go conventional, that engine will outlast the car.