Should have mentioned this sooner.
We talk a lot about exotic oils like Redline and Royal Purple. But these can be very hard to find locally. Here's one that's not:
They market this stuff for bikes, but it would do just as well in a car. Bike engines see a lot more stress with sportbikes redlining in the 12k-15k rpm range. Air-cooled bike engines also see a lot of thermal stress (sounds like a turbo motor, no?). You could almost call an oil designed for racing bikes to be overkill for a street car.
This is no johnny-come-lately marketing outfit either. They've been around forever and their expertise has been proven under the toughest conditions on the racetracks of the world.
Best of all, this stuff is really easy to find. I believe every sportbike shop in the Denver Metro area carries the stuff. Other markets are no different. Plus the 0w-40 weight is perfect for our cars.
Bike shops are a great place to find all sorts of specialty lubricants. Let's face it, the average car driver doesn't give a crap and buys the cheapest thing available. Sportbike riders are obviously a lot more tuned in to performance.
Another brand they often carry is Silkolene. This is excellent stuff as well as the maker is heavily involved in the aerospace industry. They have development contracts with the US Air Force.