The 300 horse '03 Linc Navigator requires 91 octane. Does anyone with one have real world data, SOTP, or knowledge concerning the use of lower octane with this vehicle...?

 

My Aviator calls for the higher octane.
I run the middle grade and cannot tell a difference.
The lowest swill may cause engine damaging spark knock.

 

Isn't there a knock sensor that will reduce timing..?

 

Yeah, but it can only retard the timing a certain amount. That amount may not be enough to prevent spark knock.

 

are you talking about detonation?

what is the compression ratio of the 4 valver?


just for the hell of it.... my winter beater 91 olds calais quad 4 says it needs premium gas, but i have only ever run 87 octane in it....206,000 miles later, and it still is fast and efficient....and never anything detrimental has occured...