Aeye, congrats on your new GLS SE ASX. I think its quite alright to use the higher octane fuel such as the xcs. THe vehicle manual specifies the minimum octane requirement (approx. 91) as well as the allowed ethanol content of fuel (upto 20%). I'm currently using xcs for my ASX. Brought it to Diamond motors valle verde C5 yesterday for 1k km. check. Cost me around 3.5k (free labor only, fully synthetic oil).

Quote Originally Posted by aeye View Post
I've been researching and learned that all our gasolines here are already unleaded (including the premium and high octane variants).

My agent told me to only use unleaded gasoline (assuming she meant Caltex Silver and etc.). However, I wanted to try out Petron XCS (since people say its pure and doesn't contain ethanol w/c could harm your engine in the long run).

Any comments? Mga ASX owners? or even Lancer EX owners? (I think we have the same engine)