I've been running Helix Ultra ECT C2/C3 0W30 (PP Euro LX) in my Saab turbo for 3 years (since I got it.) The lifter clatter on startup is gone, the fuel economy has improved and the oil consumption has fallen.
It's expensive, but with a VI of over 200 and HTHS >3.5 loads of Boron it's hard to top.
Jordan