What kind of gas does a Lexus LS 400 take?
Most Lexus LS 400 models run on regular unleaded gasoline (87 octane or higher in the United States). Premium fuel is not required, though higher-octane fuel may be preferred in some markets or under certain driving conditions to prevent engine knocking.
Fuel basics for the LS 400
The LS 400’s 1UZ-FE V8 is designed to run on unleaded gasoline. Octane requirements vary by market and model year, so it’s important to check your owner’s manual for the exact specification that applies to your car.
Here is a quick guide to octane expectations by region:
- United States, Canada, and many other markets: Regular unleaded gasoline with an octane rating of 87 AKI (the typical “87” you see at U.S. pumps). Higher octane fuels are acceptable but not required for daily driving.
- Europe, the United Kingdom, and many other regions: Premium unleaded gasoline is common, typically 95 RON or higher. Using premium is common practice for performance and to match regional fuel standards.
- Other markets: Always refer to the owner’s manual. In most cases, unleaded gasoline with an octane rating appropriate for your region is recommended.
In practice, the LS 400 will operate on regular unleaded fuel in most markets. If your manual indicates a higher octane is preferred or required, follow that guidance. If you hear engine knocking, switching to a higher-octane fuel can help, but it may not always be necessary for everyday use.
When to consider higher-octane fuel
Using higher-octane fuel has potential benefits and downsides. Here is a quick look at when it might matter for the LS 400:
- Pros of higher-octane fuel: Reduces or eliminates engine knock under heavy load, can improve driveability in hot weather or during towing, and may offer smoother idle in some conditions.
- Cons of higher-octane fuel: Higher price, and most LS 400s do not gain noticeable performance from regular premium fuels.
- When to use it: If you hear knocking or pinging under load, or if your owner’s manual specifies premium fuel for your exact model/year.
To ensure you’re using the right fuel, always verify with your vehicle’s owner’s manual and check the fuel-cap sticker if present. Regional differences exist, especially between the US and European markets, so confirm based on your car’s year and market.
Practical fueling guidance
Adhering to robust fueling practices helps protect the engine and maintain optimal performance. Consider the following steps when refueling your LS 400:
- Always check the specific octane rating recommended for your model year and market in the owner’s manual.
- Use reputable gasoline brands and avoid frequent switches between fuels if you notice pinging or rough running after a fuel change.
- If your engine ping occurs in hot weather or under heavy load, try a higher-octane fuel and see if the condition improves, but revert to the standard recommendation once conditions stabilize.
Bottom line: For most LS 400s, regular unleaded gasoline rated at 87 octane or higher is adequate in daily use. Premium can be used if desired or required by your regional manual, and may help prevent knocking under certain conditions.
Summary
The Lexus LS 400 generally takes regular unleaded gasoline (87 octane in the United States, with higher-octane fuels acceptable). European markets typically use premium fuels around 95 RON or higher. Always follow the model-year and market-specific guidance in your owner’s manual. If you experience engine knocking, consider higher-octane fuel, but for everyday driving, regular gasoline is usually sufficient. Regular maintenance and adherence to manufacturer guidelines help preserve the LS 400’s performance and longevity.
