Can I put regular gas in my BRZ?
Regular gasoline is not recommended for the BRZ. Subaru specifies premium unleaded gasoline with an octane rating of 91 or higher to maintain optimal performance and engine protection. Using regular fuel can cause knocking, reduce power, and may impact long-term reliability if used regularly.
Why the BRZ requires higher-octane fuel
The BRZ is equipped with a high-compression, naturally aspirated engine that relies on precise timing to maximize power and efficiency. Higher-octane fuel resists detonation (knock) better than regular gasoline, allowing the engine to maintain its designed timing and responsiveness. When lower-octane fuel is used, the engine's knock sensors may retard timing to prevent damage, which can lead to noticeable drops in performance and efficiency.
Understanding octane and its impact on performance
Octane is a measure of a fuel's resistance to pre-ignition under compression. In engines like the BRZ, higher-octane fuel helps prevent knocking during aggressive acceleration or spirited driving. If your BRZ is tuned for premium fuel, running regular can trigger knocking under load, prompting the ECU to adjust timing and potentially reducing horsepower and throttle response.
What to expect if you fill with regular gas
Before the following list, note how regular fuel can affect the car's behavior during normal and spirited driving.
- Potential loss of peak horsepower and slower throttle response due to timing being retarded to prevent knock.
- Lower real-world fuel economy as the engine works harder to achieve the same performance.
- In some cases, persistent knocking can lead to longer-term stress on engine components, though modern engines are designed to cope with occasional variations.
- Temporary warnings or hesitation in full-throttle or high-load situations until the ECU stabilizes with premium fuel again.
Concluding: While the vehicle will run on regular fuel in a pinch, you should refuel with premium as soon as possible to restore optimal performance and efficiency, and to avoid potential risk to performance under high-load driving.
Practical steps if you only have regular gas on hand
Plan ahead and minimize any sustained use of regular fuel. The following steps help manage the situation until you can refill with premium.
- Avoid aggressive driving, high-load acceleration, and sustained high RPM operation until you can refuel with premium.
- Fill up with premium as soon as possible and return to normal driving to allow the engine to regain its intended timing and performance.
- If you hear knocking or pinging, ease off the throttle and reduce engine load; avoid pushing the engine until you have premium fuel again.
- Consider a short period of moderate driving with premium after refueling to let the ECU recalibrate to optimal timing and fuel maps.
- For ongoing reliability and warranty considerations, stick to the manufacturer-recommended octane going forward and consult your dealer if you have concerns about repeated use of lower-octane fuel.
Concluding: Regular fuel should not become a habit in a BRZ. A one-off emergency fill is generally acceptable, but premium fuel should be used as soon as possible to protect performance and engine health.
Regional guidance and fuel compatibility
Fuel octane ratings vary by market, and regional specifications reflect local fuel characteristics. In the United States, premium commonly means 91–93 octane (R+M/2 method). In many European, Middle Eastern, and Asian markets, higher-octane fuels are labeled in RON (for example, 95–98 RON). Always follow the octane recommendation in your specific owner’s manual and consider regional fuel standards and ethanol content when choosing fuel.
Additionally, most BRZ manuals indicate compatibility with standard gasoline containing typical ethanol blends (such as E10) common in many markets. Always check your owner's manual for exact guidance on ethanol content and any regional caveats.
Summary
The BRZ is designed to run best on premium unleaded gasoline with an octane rating of 91 or higher. While regular fuel might run in a pinch, it can reduce performance, efficiency, and, if used repeatedly, potentially affect long-term engine health. For optimal performance and to preserve warranty assumptions, refuel with premium as soon as possible and adhere to the octane guidance in your market.
Can you put regular gas in a BRZ?
No, a Subaru BRZ does not take regular gas; it requires premium unleaded gasoline with an octane rating of 91 or higher. Using regular gas can lead to reduced performance and potentially harm the engine over time due to its high-compression engine design, though the engine's management system can adjust to prevent immediate damage.
Gas requirements
- Required: Premium unleaded gasoline with an octane rating of 91 or higher.
- Recommended: 93 octane for the best performance and efficiency.
- Acceptable alternative: 91 octane is acceptable if 93 is not available.
Why regular gas is not recommended
- Engine design: The BRZ has a high-compression engine that is designed to work with the anti-knock properties of premium fuel.
- Risk of damage: While the engine management system will adjust to prevent pre-ignition, consistently using lower-octane fuel can lead to reduced performance and may cause engine damage over the long term.
Is it okay to run regular gas in a premium car?
No, you should not put regular gas in a car that requires premium fuel because it can cause engine knocking, reduce performance, and potentially void the vehicle's warranty. Modern cars with the correct sensors may adjust to prevent damage, but this often leads to reduced power and efficiency, and the engine is still at risk of long-term damage from prolonged use.
Risks of using regular gas
- Engine knocking: Lower octane fuel can cause premature ignition in the engine, leading to a knocking or pinging sound that indicates stress on engine components.
- Reduced performance: You may experience slower acceleration and a general decrease in the vehicle's power and fuel efficiency.
- Engine damage: Consistent use of regular gas can cause significant wear and tear on engine parts over time, potentially leading to costly repairs.
- Voided warranty: Using the wrong fuel can violate your car's warranty, meaning the manufacturer may deny coverage for any engine-related problems.
What to do if you have no choice
- Drive gently: Avoid hard acceleration, heavy loads, and high RPMs to minimize the risk of engine knock.
- Add an octane booster: You can purchase an octane booster from an auto parts store to add to the tank with regular gas.
- Refill with premium soon: As soon as you can, add premium gas to raise the octane level. Mixing fuel is generally not a problem.
When it might be okay
- Some cars that "recommend" premium but don't "require" it can run on regular with a slight reduction in performance. Check your owner's manual to see if your vehicle falls into this category.
What happens if I use 87 octane instead of 91?
If your car requires 91 octane, using 87 can lead to engine knocking, reduced performance, and lower fuel efficiency, as modern engines try to compensate for the lower octane fuel. While a single use is unlikely to cause permanent damage, persistent use of lower octane fuel can lead to engine component damage and potentially void your warranty. If you accidentally put in 87, it's best to fill up with the recommended 91 on your next fill-up to correct the issue.
What happens if you use 87 in a premium-required vehicle
- Engine knocking: The engine may produce a knocking or pinging sound because the lower-octane fuel can autoignite under pressure and heat before the spark plug ignites it.
- Reduced performance: You may experience a loss of power and decreased fuel economy.
- Engine's self-correction: Modern engines have sensors that detect knocking and will adjust engine timing to prevent damage. However, this correction results in reduced efficiency and performance.
- Potential for damage: In the long term, consistently using the wrong octane can lead to more significant engine damage.
- Voided warranty: In some cases, using the wrong fuel can void your vehicle's warranty.
What to do if you accidentally use 87 octane
- Use it up and switch back: The easiest option is to simply use up the fuel in your tank. On your next visit to the gas station, fill up with the recommended 91 octane.
- Consult your owner's manual: The manual will provide specific guidance for your vehicle.
- Consider an octane booster (with caution): Some people use an octane booster to increase the octane level, but always follow the product's instructions carefully.
- Note for modern engines: Modern cars with knock sensors are more likely to be able to handle a single tank of lower-octane fuel without immediate damage compared to older vehicles, notes Quora users.
Can I put regular gas in my Subaru?
Most Subarus can use regular 87-octane gas, but high-performance models like the WRX STI and BRZ require premium fuel. You should always check your specific model's owner's manual to confirm its fuel requirements. Using premium gas in a car designed for regular fuel will not provide benefits and is not recommended.
Regular gas is suitable for most models
- For most standard Subaru models, such as the Crosstrek, Outback, and Forester, regular 87-octane gasoline is sufficient.
- Using a higher-octane fuel in these vehicles will not improve performance or efficiency.
Premium gas is required for performance models
- Certain models, including the WRX, WRX STI, and BRZ, have high-compression or turbocharged engines that require premium fuel to prevent engine knock and maintain peak performance.
- Using regular gas in these specific models can lead to a loss of power and may cause engine damage over time.
How to be sure
- Check the owner's manual: The most reliable source of information is your vehicle's owner's manual, which specifies the correct fuel type.
- Look for a warning label: Some models will have a warning label on the inside of the fuel door or near the gas gauge indicating the required fuel grade.
