Does a 2013 Honda Civic SI need premium gas?
Yes. The 2013 Civic Si requires premium unleaded gasoline with an octane rating of 91 or higher to maintain its designed performance and efficiency; using regular 87 octane can trigger engine knocking and reduce power output.
What the manual and manufacturer say
Honda’s guidance for the 2013 Civic Si centers on using high-octane fuel to suit the engine’s high compression ratio. The owner’s manual specifies premium unleaded gasoline with an octane rating of 91 or higher. While some drivers may occasionally run lower-octane fuel in other models, doing so in the Si can lead to knocking, reduced performance, and potential long-term wear. In the United States, typical gasoline contains up to 10% ethanol (E10), which is generally compatible, but higher-ethanol blends (like E15 or E85) are not recommended unless explicitly stated by Honda.
Octane and fueling options
The engine’s high compression means octane choice directly affects performance. The following options are commonly encountered by Civic Si owners:
- Premium gasoline (octane 91 or higher): Recommended to meet the engine’s timing and efficiency targets.
- Regular gasoline (octane 87): Not recommended for this model; can cause knocking and reduced power, especially under load.
- Mid-grade gasoline (octane around 89): Not officially endorsed for the Si; performance benefits over regular are uncertain, and premium remains the official choice.
- High-ethanol blends (E15, E85): Generally not compatible with the Civic Si; stick to fuel with ethanol content Honda approves (typically E10 in the U.S.).
Bottom line: to preserve the engine’s designed performance and reliability, use premium fuel as recommended.
Practical fueling tips
Additional guidance helps ensure you’re fueling appropriately and maintaining engine health:
- Choose reputable stations to ensure consistent octane ratings and fuel quality.
- If you notice unusual knocking, pinging, or loss of power, refuel with premium as soon as practical and monitor for improvement.
- Follow the manual’s guidance on ethanol content; in the U.S., this typically means standard E10 is acceptable, while higher ethanol blends should be avoided unless Honda confirms compatibility.
Sticking to the recommended fuel helps maintain performance, fuel economy, and the vehicle’s warranty protections when applicable.
Summary
The 2013 Honda Civic Si is designed to run on premium unleaded gasoline with an octane rating of 91 or higher. Regular 87-octane fuel can reduce performance and may cause knocking, especially under load. In the U.S., standard gasoline with up to 10% ethanol is usually acceptable, but higher-ethanol blends should be avoided unless explicitly approved by Honda. Always consult the owner’s manual for region-specific guidance and consider sticking to premium fuel to preserve the Si’s performance and reliability.
