Originally Posted By: Cuore_Sportivo
With such a bad base, reported sludge in the engines and high price in the end what is good about it apart from official Fiat approval?
99% of all today's synthetics are made with HC base oil and some PAO and Esters to boost low temperature pumpabilty. Nothing wrong with that. Group IV and V oils are mostly for racing, and majority of them don't carry manufacturer approvals simply because they are not intended for use that involves long drains.
I'm not saying that Star P.E. is good oil ( I've never tried it ), but it's not bad because of base oil used to make it.
You say those engines develop sludge. Sludge is a result of oil oxidation and thickening.
So if I'm not mistaking yours Super Fire has a 3 litre oil pan. Rediculusly small pan for a turbocharged engine. On top of that Fiat specified C3 /S2 oil in that engine. C3 oils are not nearly as strong as A3 oils, so if you are out of warranty you should try A3 with Fiats Z2 specification witch is full saps, long drain.
M1 0w40 comes to my mind ay first though.