Reviews of STP fuel additives

I bought a bottle a few years back. It tasted like STP. Would not recommend.

I recently used STP 5 in 1 on my 80k 2011 diesel engine. I have noticed no benefits from using it after adding it to a full tank and emptying it.

STP concentrated formula has worked out for me increasing mileage slightly on some old cars I've got running again

I like using the STP All-In-One if I can find it. Very nice and reliable imo

I have no idea why I do it, but I throw a $4 botle of STP in my gas 1 or 2 times a year in probably all my cars. I feel like it can't hurt. I hope that maybe, just maybe, it improves my fuel injectors somehow which keeps up the good fuel economy and good power.