Hello experts and knowledgeable drivers. I recently came off the phone with both Toyota and Lexus dealership on what gas grade is required for a 2018 Lexus IS 300 AWD F sport, and both companies gave me uncomfortable answers.
Toyota said at first regular was to be used, then they changed their mind when I told them my research showed Premium is required via google.
Lexus said regular is to be used but went on to say the choice was up to me.
Google keeps showing me Premium 91 to 93 and labled " required"
My ownerâs manual is so thick I get sick from reading through those awful lot of pages.
However, I have received great help here on CarTalk in the past and this is why I am choosing to seek your help.
It is confusing, the owners manual states âUnleaded gasoline onlyâ. When premium is required the manual usually states âPremium unleaded gasolineâ.
However page 587 shows 91 octane or higher, that is premium gasoline.
The E refers to ethanol in the gasoline. The second number refers to the percentage of ethanol IN the gasoline. Normal pump gas is E10 or 10% ethanol. E85 is 85% ethanol fuel, E20 is 20% ethanol fuel. You CAN use that, if you wish, but donât HAVE to use it and it MUST have an octane rating of 91 for you to use it.
E designates the percentage of ethanol blended in to the gasoline. E10 would be 10% ethanol. E15 is 15% ethanol.
Octane is something different. You need to be putting the 93 octane in there, and it needs to have a maximum E rating of 15. Generally if gas has more than 10 or 15 percent ethanol in it, it will be clearly marked as such - either with E20/E85 or âFlex fuel only.â
You presumably spent a lot of money on this car. Do you really want to put that at risk by not reading the manual to learn how to maintain your car correctly?
Either. E10 or E15 is just the Ethanol content. Gas stations around where I live only have E10. So all grades (87, 89 and 91) octane are E10. You vehicle requires a minimum of 91 octane. So 91 or higher octane is what to use. Using a lower octane under hard acceleration could do serious damage to your vehicle.