I've never seen a study of what happens when break-in procedure isn't followed, but gradual increase in the use of the powerband every 500 miles sounds like the common "internet wisdom" on the subject. I believe that an easy break-in is meant to help gently seat all the wear surfaces in the engine. After 2K miles, this should be neatly done even when following the 4200 RPM limit in your manual. After that, the heat produced from sudden hard driving will have less of an adverse effect on the engine internals because they'll all be at a broken-in tolerance, and are otherwise designed to handle the load.
I think that you can choose the Porsche method or the "I know a guy who says" method without any significant adverse effect. Just drive smooth and easy for that first 2K, and cool the car down appropriately before parking it. After 2K, hard driving is fine so long as it's still smooth.
Frankly, any revs above 4200 in second gear on are probably extralegal, so this discussion may be moot. ;)
Mark
Thanks Mark, we appreciate your personal views on this topic.
Your reply appears well thought out, although your phrase regarding the alternate running-in philosophy, as being based upon "I know a guy who says" is not consistent with the theme we started. There it is countered by the words "Porsche engineers in the US and Canada".
This advice, provided to my service manager [they know each other], was 'unofficial' and no names were provided, but appear authentic.
Another indicator: the visit to our city by representatives of Porsche of Canada [which included the President thereof] last summer, with a selection of cars from Boxter to Panamera, for a "ride and drive" for invited customers [this to mark the opening of a new/first dealership in Saskatchewan]. All the cars were 'new', 2011 models; and the recorded miles driven were available. We were too busy driving or monitoring each model to check the values. But they left several cars with us at the dealership. The Cayman S, PDK, had only 1600 km on the odometer...~1000km. The instructor and leader of the event, a well known Canadian/International racing driver, gave no limit on the revs to be used, and the Cayman was frequently in the 5000rpm range. With free use of the PDK, 'red-line' was freqently used; and the programmed full throttle standing start, was demonstrated with the Cayman S and all the other cars.
So much for 'breaking in' the DFI engines... The Cayman S continues as a demonstrator for potential customers, who may use it fully, without the annoyance of 'by the manual driving'. It is running beautifully...
The matter of 'running -in' a Carrera/Cayman/Boxter DFI engine, remains open to interpretation.
Other insights and experiences are most welcome on this topic. I have used the alternate gradual increase of revs and throttle for all my cars over the last 20 years or so. My NSX's engine was inspected internally [at 50K miles/80K km], in search of a misfire, which turned out to be a faulty injector on one cylinder [which really should/could have been checked eralier in the search]. The engine was in perfect condition, with no signs of abnormality to pistons or cylinders...it was pronounced 'as new'. One reason for the deeper inspection was that a pending trade to a 2005 Carrera 2 was in process. The NSX, with the [inappropriately dreaded] auto-stik, but headers and sports exhaust, was almost as quick [delta 0.5/1.0 sec to 60/100 mph] and fast as the Carrera [which also was with headers and sports exhaust], once the latter was run-in. Our 997.1 was very fast and quick, compared with other local 911s. I rest my/our case.
Merci beaucoup,
ALanM, KiwiCanuck