Does the Lexus IS 350 require premium gas?
Yes. The Lexus IS 350 is designed to run on premium gasoline (91 octane or higher) for optimal performance and smooth operation. Using regular gasoline is not recommended for daily driving, as it can reduce power and efficiency in some conditions.
What the fuel guidelines say
The IS 350’s owner’s manual specifies premium unleaded gasoline as the recommended fuel. The vehicle uses a high‑compression 3.5‑liter V6, and higher-octane fuel helps preserve horsepower, throttle response, and overall engine timing. Always verify the octane requirement for your exact model year and market in the official manual or with a Lexus dealer.
Key considerations about octane choices for the IS 350 are:
- Premium unleaded gasoline (91 octane or higher) is recommended to maintain advertised performance and drivability.
- Regular unleaded gasoline (87 octane) may be used only if premium is unavailable, but expect potential reductions in power and responsiveness.
- Using higher-octane fuels (93 octane or higher, where available) is compatible and may offer marginal gains in some driving conditions, though gains vary by model year and market.
- Always refer to the owner's manual for the exact octane specification for your vehicle’s year and region, as requirements can differ slightly across markets.
In practice, premium fuel is the safest and most reliable choice for maintaining peak performance, engine smoothness, and longevity. If you must use regular gasoline temporarily, you may notice a dip in acceleration or mpg until you refuel with premium again.
Practical considerations for owners
To ensure you’re fueling the IS 350 correctly and maximizing its performance, consider these guidelines.
- Always follow the octane recommendation shown in your vehicle’s manual, which for the IS 350 is typically premium (91 octane or higher).
- Be mindful of local fuel options: octane ratings are labeled differently in some regions (AKI vs. RON), so use the local equivalent of 91 AKI or higher as a baseline.
- When traveling or refueling away from home, prioritize premium If you notice reduced performance or knocking, reset back to premium as soon as possible.
Conclusion for owners: premium gasoline is the recommended choice for the Lexus IS 350 to ensure the vehicle delivers its designed performance and efficiency. Regular fuel can be used only if premium is not readily available, but it may compromise power and responsiveness over time.
Market and year considerations
Is this the same across all model years?
Across most model years and markets, Lexus has aimed to keep premium unleaded gasoline as the recommended fuel for the IS 350’s 3.5‑liter V6. Some regions may label octane differently, but the underlying guidance remains: premium fuel supports optimal engine performance. Always check your specific year’s owner’s manual or consult a local Lexus dealer to confirm the exact octane requirement for your vehicle.
Summary
In short, the Lexus IS 350 is designed with premium gasoline in mind. Using 91 octane (or higher, depending on your region) is the recommended option to maintain peak horsepower, smooth acceleration, and overall engine health. Regular gasoline may be used only if premium is unavailable, but expect reduced performance until you refuel with premium again.
