Absolutely use ONLY white gas. NO unleaded. While it will work for a while, eventually the additives will gum up the works and ruin the lantern. While white gas can be left in for YEARS with no adverse effects.
White gas may be around $10/gal or more, but so what? You know how long that will last? Like forever!
And forget about D-cell -powered flashlight lanterns. That's not even close to the level of illumination of gas or propane-powered lanterns. Like 10% or less.
(Unless you plan to use your lantern inside. The CO will kill you, or you might set yourself on fire.)