I think the Low Speed Pre-ignition problems have negatively or at least hindered AMSOIL Signature Series oils. Comparatively speaking they do use more detectable additives compared with other synthetic oils that have lowered calcium levels and also use combination of calcium/magnesium wear package. However-Amsoil's previous formula was absolutely loaded with Calcium like 3500 or more and still included moly and boron. I think the older formula resulted in maintaining a higher tbn throughout extended drain intervals. In several used gasoline oil analysis reports-it seems Amsoil's tbn does not hold up as well as previous formula. Virgin oil analysis also has shown a starting tbn of 9 as opposed to 12.5 on data page. Wondered if others have noted similar general observations or am I over-generalizing or not seeing this potential trend accurately.