[19bonestock88]

I googled the energy densities of the two fuels. I did have to guess that diesel has 0 octane rating, based on the fact that an Otto cycle engine and a diesel cycle engine use the opposite forms of combustion, I couldn’t find a rating...

I guessed at the ratio to still keep the mixture at at least 87 AKI octane, to prevent definite engine damage, averaging diesel in at 0 octane... if it were, say, rated at 60, things would change some, in that you could run more diesel in gasoline and still have a mixture average of 87, but it wouldn’t boost the energy density of the resultant fuel enough to bother with, IMO... if mixing some diesel in makes the fuel mix cheaper than straight gasoline, then it could be a feasible option for reducing your fuel bill but I don’t believe it will boost efficiency enough to see from tank to tank