- I own a 2004 Screaming yellow convertible with 11,000 miles. I am a new member to this form. My question to you guys is about fuel. In my area I can get 91 octane leaded fuel. I know the car calls for 92 octane. I can also use 93 octane Sunoco unleaded . Is it still about the octane number or would the 91 leaded be better? Grady