In case you’re looking for some good reading material but are feeling the pinch of the slow economy, the latest edition of Porsche’s official magazine Christophorus is now available for free on your iPad. And included among the interviews, adventure stories and automtive profiles lies the nugget you see above you: a very cool composite infographic comparing the original 901 series Porsche 911, the outgoing 997 series and the piping-hot 991 series.

It’s one thing to look up the specs and see just how far the 911 has grown over its 48 year lifespan, in both overall length (6.73 inches) and in wheelbase (5.52 inches); it’s something completely different to see their silhouettes superimposed on top of one another. Now, excuse us while we try to arrange a group test of all three of these at the same time, so we can share firsthand just how much they’ve changed.

(Should you feel like exploring the whole issue of Christophorus, you can click here to go to the iTunes Store and download it.)

[via Teamspeed]