Does Lexus 350 require premium gas?

Most Lexus 350 models with the 3.5-liter V6 are designed to run on premium gasoline (octane 91 or higher in the United States). Regular gasoline can be used only in emergencies, but it is not recommended for everyday driving because it may reduce performance and efficiency.

Fuel requirements for the Lexus 350 family

Which models are covered

The label “Lexus 350” spans several models that use the 3.5-liter V6, including the ES 350, RX 350, GS 350, and LS 350 across recent generations. While the exact octane recommendation can vary by year and market, the general guidance remains consistent: premium gasoline is the preferred choice for optimal performance.

Key guidance on octane and usage in the 350 lineup

• Premium gasoline (octane 91 or higher in the United States) is typically the recommended fuel for 3.5L V6 engines in Lexus 350 models to maintain peak performance and efficiency.


• Regular unleaded gasoline (87 octane) is generally not recommended for normal operation; if used, you may experience reduced power, slower acceleration, and lower fuel economy. Some markets allow emergency use of lower-octane fuel for a limited time, but this is not intended for regular driving.


• Always verify the exact requirement for your specific model year and market by checking the owner's manual or the fuel label on the fuel door, since requirements can differ slightly by generation and region.

Bottom line: Premium gas is the recommended baseline for the Lexus 350 family, with regular gas discouraged for routine driving. Always confirm the exact specification for your vehicle year and market.

Practical guidance for drivers

How to verify octane requirements

To be certain, consult three sources: the owner's manual, the fuel-filler door label, and the dealership or official Lexus website for your exact year and market. Octane requirements can shift with new generations or regional standards, so cross-checking is prudent.

Fueling best practices to protect performance

• Use the octane grade specified by the manufacturer (typically 91+ in the US; higher RON grades in many other markets).


• If premium is temporarily unavailable, refer to your manual to see whether 87 octane can be used briefly and under what limits; do not rely on regular gas for long periods.


• When possible, choose Top Tier gasoline brands, which include detergents that help keep the engine clean and maintain performance.

Conclusion: Adhering to the recommended octane enhances reliability, power delivery, and efficiency, while straying to lower-octane fuel can degrade performance over time.

Summary

In short, Lexus 350 models with the 3.5L V6 generally require premium gasoline (91 octane or higher in the US; higher RON in many other markets) for optimal performance. Regular gasoline is not advisable for routine driving, though it may be permitted in emergencies according to the manual. Always verify your specific model year and market to be sure, using the owner's manual or fuel door label as the definitive guide.

Can Lexus RX 350 use regular gas?

Whether you can use regular gas in a Lexus RX 350 depends on its model year; models from 2012–2022 can use regular (87 octane) unleaded, while newer models from 2023 and beyond typically require premium (91 octane) unleaded gas. It is crucial to check your owner's manual for the correct fuel requirement to avoid potential engine issues like reduced performance, increased emissions, or damage. 
2023 and newer RX 350 models

• Most newer models with a turbocharged engine require a minimum of 91 octane premium unleaded gas.
• Using regular gas in these models is not recommended and can lead to decreased engine performance and mileage. 

2012–2022 RX 350 models

• These models are designed to run on regular unleaded gasoline (87 octane). 
• While you can use premium gas, it is not required and will not provide significant performance benefits. 

Important considerations

• Always check your owner's manual: This is the most reliable source for your specific vehicle's fuel requirements. 
• Avoid high-ethanol fuel: Do not use gasoline with more than 15% ethanol, and avoid fuels containing methanol or MMT. 
• Consider the long-term cost: For newer models requiring premium gas, the cost of using the correct fuel is a long-term investment to ensure proper performance and longevity of the engine. 

Which Lexus models do not require premium gas?

Several Lexus models do not require premium gas, including the Lexus ES 350, RX 350 (older models), NX 250 (some model years), and hybrid models like the UX 250h and NX 350h/450h+ (where premium is recommended but not required). To confirm the correct fuel for a specific vehicle, always check the owner's manual or the vehicle's fuel-door label. 
Models that typically use regular unleaded (87 octane) 

• Lexus CT 200h
• Lexus ES 300h and ES 350
• Lexus HS 250h
• Lexus NX 250 (some model years)
• Lexus NX 300h (older models)
• Lexus RX 350 (models from approximately 2012-2022)
• Lexus UX 250h (some model years) 

Models where premium is recommended but not required 

• Some hybrid models, such as the NX 350h and NX 450h+, can use regular gas, but using premium is recommended for optimal performance and to prevent potential engine knocking. 

How to be certain

• Check the owner's manual: This is the most reliable source of information for your specific vehicle. 
• Look at the fuel door: The required fuel type is often listed inside the fuel-filler door. 

What happens if I put regular gas in a Lexus?

If you put regular gas in a Lexus that requires premium, you may experience reduced engine performance and hear engine knocking, especially under heavy acceleration. While a one-time mistake likely won't cause lasting damage, consistently using regular gas can lead to long-term engine problems over time. Check your owner's manual to confirm if your specific Lexus model actually requires premium fuel, as some models are designed to run on regular gas. 
Potential effects of using regular gas

• Reduced performance: You may notice a decrease in power and acceleration. 
• Engine knocking: The engine may "knock," which is a harsh metallic sound caused by premature or uneven combustion. Consistently ignoring this can lead to engine damage. 
• Engine damage: Over time, continuous use of regular gas in an engine designed for premium can cause serious, long-term damage. 

What to do

• Check your manual: First, consult your car's owner's manual to see if your model genuinely requires premium gas. Many Lexus models, especially certain SUVs and hybrids, are designed to run on regular 87-octane fuel without issue. 
• If you accidentally used regular: If your car requires premium but you've put regular in, don't panic. It's best to avoid hard acceleration or heavy driving until you can top off the tank with premium fuel. Your car's computer will adjust the engine timing to compensate for the lower octane, preventing damage from a single fill-up. 
• If you consistently use regular (when premium is required): This is when you risk serious engine damage. The long-term effects of engine knocking and underperformance can lead to costly repairs. 

Does Lexus IS 350 require premium gas?

Yes, the Lexus IS 350 requires premium unleaded gasoline, specifically 91 octane or higher. Using a lower octane fuel can lead to underperformance, and while a single tank of regular gas won't necessarily cause damage, repeated use of lower octane fuel can negatively impact the engine over time. 

• Recommended fuel: Premium unleaded, 91 octane. 
• Why it's important: The engine is designed for premium fuel to perform as intended. Using regular gas can lead to reduced power and efficiency. 
• What happens with lower octane: While the car's computer can adjust for lower octane fuel, using regular gas consistently can lead to long-term performance issues. 
• If you can't find premium: The owner's manual states that if 91 octane is unavailable, you can use a lower-octane fuel, but you should return to using premium as soon as possible to avoid potential engine issues.