The Castrol Edge 5W-40 A3/B4 Euro oil still lacks the API SP rating, as do several other competing Euro formulations. Two of the several improvements of the API SP rating over the SN predecessor are 1) a reformulation to help protect against low speed pre-ignition (LSPI), and 2) a test for timing chain elongation. While the European ratings (VW 505, MB 229.5, Porsche A40, BMW LL-01) are more demanding in general than the SP rating, do they adequately address these two areas of concern? While I am not too worried about LSPI, cam chains and tensioners seem to be the least reliable internally lubricated component in modern engines and are costly to repair. No question that some tensioner/chain problems are due to poorly designed hardware and over extended oil changes, but is part of the problem attributable to a weakness/oversight in the European specs themselves? Thus is it worth dropping Castrol for the latest Pennzoil and Quaker States reformulations that are SP compliant to get extra protection? And what's taking Castrol (and others) so long to switch over to SP in its Euro lineup? Thanks.