I had a friend that happened to not too long ago. He wanted to make his family mini van go a little faster so he dumped a bottle of that high octane, and yes, lead added, additive in his fuel. Well, it only took two tanks fulls of fuel with that stuff in it to make his mini van NO GO no more... He said just before it stopped running it started making this rattling noise HAAAAA. All the cats innards was rattling around in the muffler. It didn't want to start very well, and when it did, when you put your foot to the floor, it would die. If I knew he was doing this to his minivan I would have tried to warn him. Oh well.
Fritz