I've learned, too often the hard way, few of us can know with certainty much of anything. Talk to one person at INEOS, then another, you'll get different answers, both from engineers, but that's human nature, not INEOS, or INEOS's fault. True of any subject in any group or company or govt agency. When I've been asked questions as a NASA engineer it's hard to say, well, let's get some evidence, I have the urge to think I know and to say it. Testing stuff is hard, takes time, money it's arduous, and change any variable, and things change again. Look how many debates on oil viscosity and other stuff is on this forum, or on the BMW forums, or any forum. My comment was that nobody really knows, or we haven't talked to the person who does know because they've done the testing and have the evidence. And we never know when we're talking to the 'right' person. I think we have to decide when to do things ourselves, and do whatever research we can to understand the issue or what we're trying to do and then, well, who knows if we got it right? Knowing things is hard.