Point taken about Wikipedia, but for those who've been around, the 930 was a benchmark car for a LONG time, and as foggy as my memory is, all the auto raggs pegged it in the 4's. Also the Guinness book of world records used to list it as the fastest production vehicle. That's what I remember and believe.
For all intents and purposes, the 930 is a sub 5 sec. car PERIOD. Who wants to split hairs?
Driver, testing conditions, body changes, emissions, would certainly account for discrepencies of a few tenths.