I changed oil in my 997.2TT today for the first time and found an interesting, and I hope useful for others, bit of information. The manual says oil capacity with filter is 7.9 US qts. I followed the manual and added 7.9 qts (kept ~ 0.1 qts in the can).
Checked the electronic dip stick and it showed 2 out of 3 bars. I added the rest of the can (8 qts total) and now it shows 3 out of 3 bars. So it took just 0.1 qts to trigger the oil sensor to show next bar on the oil level meter. I guess Porsche intentionally specified 7.9 qts to make sure people don't overfill.
By the way, I found that changing oil on 997.2 is easier then on any other car I have had. No need to jack the car. And the telescopic retractable oil funnel is a great design feature (996TT did not have it).
I hope DIY-selfers new to 997.2 will find this useful.

 

the exact amount of oil depends upon draining time of used oil...I ve seen 996TT getting 9liters and others get 8,5liters...On the other hand 996TT had oil drain plugs for the turbo cans...where 997 doesnt...

 

thx!