Lexus Fuel Requirements

Depending on the make of your Lexus, you may be required to use a minimum of 91-octane gas. High-performance cars often require a higher octane gas to run at maximum performance levels. If your owner's manual indicates an octane level of 91 or higher, it is safest to adhere to the manufacturer's recommendations. Lexus motors are often designed with a specific grade of gasoline in mind, although they will run on lower grades if necessary. The year of your model can also have bearing on the fuel you use. The 2010 ES350 recommends 91 octane, while the 2011 model being released has downgraded that to 87.

Most mechanics agree that there is little performance difference between 87 and 89 grade octane gasoline. Lexus automobiles that do not specify a higher-grade octane for optimum performance will run just fine on 87 or 89 octane. Sometimes even when your Lexus does recommend 91 octane or higher, it will still run well on 87 or 89. This is determined by whether your model comes equipped with a knock sensor. These are most common in Lexus' 300 and 400 series models. A knock sensor can adjust the timing for different grades of gasoline. This allows your car to run well on a range of grades.

The "it's better to be safe than sorry" rule applies here. If your Lexus model specifies a particular octane grade, it is best to follow that recommendation. The cost for higher-octane fuel is not insignificant but could potentially balance out in mileage and performance. The price per gallon can run about 25 cents more per gallon for 91 octane over 87 octane--a difference of $3.75 for a 15-gallon tank. Also, when it comes to Lexus' high end sports cars, like the Limited Edition 2011 LFA, the octane grade can make a serious difference. Cars that have 500+ horsepower, like the LFA, need all the octane you can give them.