STT allows Engine Ice in the intermediate and advanced groups as well. At least they did at Putnam. It wasn't on that bike prep page, but it was on the registration form at the track. They allowed anything in novice, but you had to use water, water wetter, or engine ice for intermediate or advanced. I made sure of that before hand because I had Engine Ice and I thought I would be moving up to intermediate the second day. But, since you do a lot of track days with different groups, it would definitly be a good idea to just go the all accepted route.