2003 Toyota Matrix Regular Unleaded vs. High Octane

MVOOSEN

MEMBER
2003 TOYOTA MATRIX
4 CYL
2WD
MANUAL
70,000 MILES

Is it harmful or helpful to use high octane fuel on a unleaded fuel only tank? I know that the high octane burns hotter and helps clean out the engine. Correct me if I'm wrong. Are there any other benefits of this or harmful effects?

Tuesday, July 7th, 2009 AT 10:41 AM

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

High octane than what is recommended for your car is a waste of money. It has a different flashpoint, and will affect the engine timing. NOT used to clean anything! Combution chamber cleaner is made for that job! High compression engines require high octane. Leaded and unleaded are what counts as far as damageing the engine, using higher octane unleaded gas in a car made for regular unleaded wont harm it, but wont do any cleaning. They sell detergent gasoline in all grades!