Now I recall where I remember that scent... Mobil Drive Clean before they went to the new packaging. Does anyone else remember that smell? Before G-Man 2 replies thinking I'm trying to say M1 SS is a Group III - I'm just recalling where I remember the M1 SS smell. Pennzoil PureBase smells like popcorn and M1 drive clean had a real unique scent. M1 SS also has this scent - I wonder if some of the additives are the same?