Anybody out there have any input or experience regarding Mobil 1 ESP Formula M? It supposedly is better for cat converter life, as well as "quicker protection" according to Mobil. It costs a buck per quart more, but if it helps prolong cat life, it seems money well spent. In the Mobil literature, they refer to 5w/40. Is this an okay weight as Porsche recommends 0w/40 for my 2000 C2 (as I understand it)? Thanks as always for the great input.