Guys...I have a question about 5th gen engine.

As the title said, the engine knocks on all gears except the 1st gear and its pretty loud/bad.
Some ppl say it only needs higher octane for the gas and a tune up.

IS it true??

Any experience?

I'm in Asia right now btw, and normally ppl dont use unleaded for a car that old since its more expensive.


Thx!!