Here's my latest. Pushed it the furthest so far. ~9K miles and changed it just at 30K total. 100% of this interval was with a new turbo (was slightly used but new to me/my car) and Stage 2 software. This interval included lots of hard driving, about a dozen quarter mile launches and numerous shorter 0-60 run. I drove the crap out of it. Still probably 60% highway cruising. Liquimoly Leichtlauf High Tech 5W40 with Ceratec additive added when changed. (can see the moly/boron numbers from it) Looks like it held up great. I had zero consumption over the interval. I'll be going back to my ~7.5K change now but just was curious what 9K looked like with the hard use/extra power. Looks like it sheared to 30w but not by much. Also looks like the K&N "oh my god it will ruin engine rock-catcher" air filter is still doing a good job at filtering. Based on the data I have so far (TBN/viscosity graphs), I'd say 7.5K is a great interval to use/safe - it's 3/year for me which is fine/not overkill.