Maximo, were your tests of filled vs non filled all on equally modded engines? Were the tests done on stock vs stock? To me all your post says is what the putty does to YOUR modified engines. I am gona guess maybe 1% of the worldwide racing population uses YOUR racing engines. It almost seems as if your trying to discredit someone and what they said, so I sure hope your experience your speaking of is with more than just your own modified engines!!