Been using AMSOIL XL 5w-30 Synthetic Oil for my vehicle since 10,000km until today clock 29,500km, but of course I change intervally at every 10,000km.

The engine never feel sluggish whenever it nearly hits 9,000km and still working strong until 10,000. This engine oil is made for long lasting purpose and they claimed it can last up to 10,000 miles or 12,000 miles if I'm not mistaken. But changing oil at every 5,000km or 10,000km intervally is recommended.

I guess start from now we should use this format.

Brand:
AMSOIL

Model:
Extended Life Synthetic Motor Oil

Viscosity:
5w-30

Vehicle:
2010 Toyota Corolla Altis 1.8L

Your Feedback:
- Last longer, change in every 10,000km interval
- Engine never feel sluggish
- Fuel saving
- Light oil, engine easy to start and warm up

Reference:
http://www.amsoil.com/storefront/xlf.aspx