Does Lexus RX 350 require premium?

Yes. Lexus recommends premium unleaded gasoline for the RX 350 to preserve peak performance and efficiency; regular unleaded can be used in a pinch, but expect reduced power and fuel economy and possible engine knock under sustained load.

What Lexus says about fuel for the RX 350

The current RX 350 models are designed to run on premium unleaded gasoline with an octane rating of at least 91 AKI for best performance and efficiency. Regular unleaded is allowed if premium isn’t available, but you may notice slower acceleration, less responsive throttle, and lower miles per gallon. The vehicle’s knock sensors and engine control unit can adjust timing to prevent damage when lower-octane fuel is used, though those safeguards can come at a performance cost.

Impact of using regular fuel

Using regular unleaded typically results in a measurable drop in performance, including slower acceleration and a modest decline in fuel economy. The engine’s knock-sensing system may retard timing to prevent pre-ignition if the octane is too low, which further reduces power. The difference is more noticeable during uphill driving, towing, or when demanding driving conditions persist.

For drivers who rarely push the engine hard, regular gasoline can be acceptable for short periods when premium isn’t available, but it isn’t the ideal long-term choice.

Fuel options in practice

Here’s a practical look at how premium and regular fuels affect the RX 350’s performance and ownership experience.

• Performance: Premium provides the strongest throttle response and peak horsepower; regular may feel noticeably slower under load.


• Engine health and longevity: Premium is the designed fuel for optimal operation; regular is permissible but could limit peak performance over time if used repeatedly.


• Fuel economy: Premium often yields better efficiency; regular can reduce miles per gallon slightly, particularly in demanding conditions.


• Availability and cost: Premium is widely available but more expensive per gallon; plan accordingly in areas with limited options.

In general, sticking with premium unleaded supports the RX 350’s intended performance envelope and efficiency. Regular can be used temporarily when necessary, but plan to refuel with premium as soon as possible to restore optimal performance.

Practical tips for fueling and maintenance

These guidelines help ensure you meet the RX 350’s fuel requirements and maintain consistent performance.

1. Check your owner’s manual for the exact octane guidance for your model year and market.


2. Keep a supply of premium fuel or plan trips to stations that offer premium if you regularly drive in demanding conditions.


3. If you accidentally fuel with regular, drive normally and refuel with premium at your next opportunity to minimize any potential performance impact.


4. Avoid repeatedly filling with very low-octane fuel and consider routine maintenance to keep the engine running smoothly.

Following these steps helps protect engine performance, maintain fuel economy, and preserve the RX 350’s response across its lifespan.

Summary

Bottom line: For the Lexus RX 350, premium unleaded gasoline with an octane rating around 91 AKI or higher is the recommended fuel to achieve the vehicle’s designed performance and efficiency. Regular unleaded can be used when premium isn’t available, but you should expect reductions in power and economy, with the potential for knock under certain conditions. Always consult your owner's manual and your local Lexus dealer for guidance tailored to your specific model year and region.

What Lexus does not need 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. 

Can I use regular gas in my Lexus RX 350?

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. 

What is the weakness of the Lexus RX 350?

Early Lexus RX 350 releases experienced steering issues, notably power steering fluid leaks from the rack and pinion system. Not only is this a massive safety hazard – it can also be costly to repair.

Does the 2025 Lexus RX350 need premium gas?

Yes, the 2025 Lexus RX 350 requires premium unleaded gasoline with an octane rating of 91 or higher for optimal performance and to prevent potential engine damage. Using a lower-octane fuel can lead to engine knocking, decreased performance, and may void your warranty.
 

• Performance and efficiency: The 2025 RX 350 is engineered with a turbocharged engine that is designed to run on premium fuel, which maximizes its power output and fuel efficiency. 
• Engine health: Using the correct premium fuel helps prevent engine knocking and the buildup of carbon deposits, ensuring the long-term health of the engine. 
• Warranty: Consistently using a lower-octane fuel than recommended can potentially void the vehicle's warranty if engine damage occurs. 
• Hybrid models: If you are considering the RX 350h hybrid, the recommendation is slightly different; the manufacturer specifies that premium unleaded gasoline is required for peak performance and efficiency.