Ouch ! Yes obviously I realise that, with all the problems that brings to forecourt managers btw. FWIW , I agree that the additives are snake oil/sticking plasters too. I was referring to the incidents of agricultural machinery breaking down described in the OP. I had an issue with a wood chipper with a fuel blockage that was unusual a few months ago, could have been all the usual suspects, good to keep ones knowledge up to date, no ?
Not sure of the need to truncate my post as you did.