What oil does a 10th gen SI take?

The 10th-generation Civic Si uses 0W-20 full‑synthetic engine oil, Honda‑approved or equivalent, meeting API SP or newer standards. If 0W-20 is unavailable, a 5W-20 can be used as a temporary substitute, but you should revert to 0W-20 as soon as possible and follow your owner's manual for guidance.

The 10th-generation Civic Si (FK8, produced roughly 2017–2021) relies on a 1.5-liter turbocharged engine that engineers tune for peak performance and efficiency. Selecting the right oil matters for protection under spirited driving and cold-weather starts, so understanding the exact viscosity, certifications, and replacement intervals helps owners keep their Si running smoothly over time.

Recommended oil type and certifications

The following information summarizes the official guidance for selecting oil in the 10th-gen Civic Si. This list helps clarify the core requirements you should look for when shopping for oil.

• Viscosity: 0W-20 (full synthetic) for normal operating temperatures and climate ranges.


• Standards: API SP or newer, and ILSAC GF-6 (GF-6A/GF-6B) specification compatibility.


• Manufacturer guidance: Honda Genuine 0W-20 or an equivalent aftermarket oil that meets the above specifications.


• Substitution note: If 0W-20 cannot be found, a 5W-20 may be used as a short-term substitute per the owner's manual, but revert to 0W-20 as soon as practical.

In short, the right oil for the 10th-gen Civic Si is a 0W-20 full‑synthetic that meets API SP (or newer) and GF-6 standards, with Honda‑approved or equivalent formulations preferred. Use the 5W-20 only as a temporary fallback if 0W-20 is unavailable.

Additional considerations for oil selection

Before purchasing oil, keep these practical tips in mind to ensure compatibility and performance across seasons and driving styles.

• Choose full synthetic 0W-20 that clearly states API SP or newer and GF-6 compatibility on the label.


• Prefer Honda Genuine motor oil or reputable brands that explicitly meet the same specifications.


• Avoid regular (non-synthetic) 0W-20 or thicker oils like 5W-30 or 10W-30 unless your manual specifically calls them out for certain conditions.


• Do not rely on oil that does not certify the required viscosity and standards; using an out-of-spec oil can affect protection and warranty coverage.


• Always consult your owner's manual for model-year-specific guidance and follow the recommended service intervals, which are often managed by the vehicle’s oil life monitor.

Properly selecting oil according to these guidelines helps maintain engine performance, efficiency, and long-term reliability, especially under the sporty usage patterns often associated with the Civic Si.

Summary

For the 10th-generation Civic Si, the standard oil is 0W-20 full synthetic that meets API SP or newer and ILSAC GF-6 standards, with Honda Genuine or equivalent brands preferred. If 0W-20 is temporarily unavailable, 5W-20 can be used as a short-term substitute per the manual. Always refer to the specific model year in the owner's manual and adhere to the oil life monitor's guidance for change intervals.

What oil for 2018 Civic Si?

The recommended oil for a 2018 Honda Civic Si is 0W-20 full synthetic oil, which can be Honda's own brand or another high-quality brand that meets the specifications. Using this specific oil ensures optimal performance and engine longevity as recommended by Honda engineers. 

• Recommended oil: 0W-20 full synthetic. 
• Why it's recommended: This specific viscosity is engineered for the engine's performance and fuel efficiency. 
• What to avoid: Do not use conventional or conventional/synthetic blend oils in a non-emergency situation, as the engine is not designed for them. 
• Alternative for aggressive driving: For some aggressive driving situations, a thicker oil like 5W-30 might be considered, but it's best to confirm with a dealer to ensure it's acceptable for your specific engine and driving conditions. 

What engine does a 10th gen SI have?

The Civic Si was unveiled in November 2016 as a prototype model at the Los Angeles International Auto Show. It is powered by a turbocharged 1.5-litre engine available exclusively with a 6-speed manual. Performance features include active shock absorbers, active steering and a limited-slip differential.

Can I use 5w30 instead of 0W20 in my Honda?

You should stick with the recommended 0W−200 cap W minus 200𝑊−20 oil for your Honda, as using a thicker 5W−305 cap W minus 305𝑊−30 oil can reduce fuel economy and may cause increased wear over time. While it might not cause immediate damage, especially in warmer climates, it's not advisable to stray from the manufacturer's specification unless the owner's manual explicitly allows for it in certain conditions, like extreme heat or heavy use. 
Potential impacts of using 5W−305 cap W minus 305𝑊−30

• Fuel economy: 0W−200 cap W minus 200𝑊−20 oil is designed to be more fuel-efficient. Using a thicker 5W−305 cap W minus 305𝑊−30 oil will likely decrease your miles per gallon (MPG). 
• Engine wear: The recommended 0W−200 cap W minus 200𝑊−20 is selected for the specific engine design. Using a thicker oil can impede the flow of oil to crucial engine components, potentially leading to increased wear over the long term, particularly on cold starts. 
• Engine efficiency: A thicker oil can reduce overall engine efficiency, and in some modern engines, it can affect the performance of parts designed for the thinner oil. 
• Warranty: Using the wrong oil could potentially void your warranty, so it's best to follow the manufacturer's recommendation to avoid issues. 

When using a different oil might be considered

• Owner's manual: Check your owner's manual to see if it lists 5W−305 cap W minus 305𝑊−30 as an acceptable alternative for specific conditions, such as very hot weather or if 0W−200 cap W minus 200𝑊−20 is unavailable.
• Extreme heat: In a very hot climate, some manuals might suggest a thicker oil like 5W−305 cap W minus 305𝑊−30 for heavy-duty use, such as towing. However, this is an exception, not the rule, and you should confirm it in your manual. 

What kind of oil does a Honda Si take?

The recommended oil for a Honda Civic Si is a full synthetic 0W-20 oil. For the transmission, the 2016+ models with a limited-slip differential (LSD) require 75W-90 gear oil. It is always best to consult your owner's manual for the most accurate and specific information for your vehicle's model year. 
Engine oil

• Type: Full synthetic
• Weight: 0W-20
• Recommendation: Use Genuine Honda 0W-20 motor oil or another quality brand that meets the same specifications. 

Transmission oil (for 2016+ Si models with LSD) 

• Type: 75W-90 gear oil
• Recommendation: This oil is designed to work with the limited-slip differential and can improve shifting performance.