I honestly think Lucas oil additives are pretty good oil additives. Though I have heard clams of Lucas oil additives messing up peoples cars I have saw in my own car that I actually get 25% better fuel mileage than before.
I don't believe any oil additive can make 25% better fuel economy. Not even going from straight 60 weight to a 0w20 would make that much difference.
Look back at this poster's history, it has been a record of nothing but post after post for additives. He's been questioned about it before by myself and others but never returns to any of those questions to discuss his posts.
And you're right that no additive can give that kind of improvement. You can't change the laws of physics with an additive, even if you buy it at Dollar Tree.
I think this poster has been around before and it's not his first rodeo at Bitog.