If you have the 3.0 liter FFV ( flexible fuel vehicle ) engine
no
A 2000 Lesabre is not designed for E85. While the car might operate on E85 the fuel system is not built for it.
I was looking at the 2003 Ford Ranger Owner Guide and it shows for the 4.0 liter SOHC , V6 engine ( " regular " unleaded gasoline , 87 octane ) So , the answer is ( no ) * there was a flex fuel version of the 3.0 liter " Vulcan " V6 engine available that used either 87 octane unleaded gasoline , E85 , or any combination of the two fuels
The 2002 Ford Explorer runs on flex-fuel (unleaded/E85).
The 2012 Ford Expedition runs on flex-fuel (unleaded/E85).
The 2013 Ford Focus runs on flex-fuel (unleaded/E85).
The 2013 Ford Taurus runs on flex-fuel (unleaded/E85).
The 2014 Ford Focus runs on flex-fuel (unleaded/E85).
The 2013 Ford Expedition runs on flex-fuel (unleaded/E85).
The 2014 Ford Expedition runs on flex-fuel (unleaded/E85).
The 2012 Ford Focus runs on flex-fuel (unleaded/E85).
The 2013 Ford Explorer runs on flex-fuel (unleaded/E85).