I have had a few newer Porsches, waiting for the 997.1/.2 GT3 RS to drop more in price before picking up another P-car, but so far I've had...
- 2001 911 Turbo S from 38k to 57k
- 2006 Boxster S that was supercharged by the PO from 41k to 63k
- 2010 Cayman S from 27k to 35k
- 930 Turbo w upgraded KKK K04 Turbos
- 914 with a 3.8L Carrera S motor
I went from M1 0W40 to RL 5W40 and 5W50, and can honestly say that I never had a single issue. The oil temps on track were better by 18 to 30 degrees Fahrenheit going to RL 5W40, and I never lost a quart of oil.
I wish I still had a few of those, but BMW are my first love, and the only car that is free of a Roundel that will find itself in my "favorite car spot" in the garage, is a GT3 RS (4.0). Turbos are too soft, IMHO, too much compromise and I abhor AWD on anything that is supposed to be a performance vehicle. The GT2 are nice, but despite the power, and proper driven wheels, they are not really suited for track use without 10s of thousands in changes, but the limits are orders of magnitude greater than anything ever acceptable on the street.
The GT3 RS, well, I will just say that the first day I spent in one at the track, I was setting times as much as 7 seconds faster than stock Turbos, and I am far from a great driver (I consider myself mediocre). But to get into a car and be running with, or passing, significantly more powerful cars in the first 3-4 laps, it speaks volumes of the car's inherent ability.