Ok it is not in the Ferrari just yet but it will be soon. Up to recently I used Mobil 1 15W50 in my daily driver, a 4x4. The car has self adjusting tapets and it had started sounding like a diesel engine with very audible clatter. For the last 2 oil changes I used 0W40 and it is like a totally different vehicle. Quiet, revs smoothly and happily and easily hits 170 kmph without any hesitation what-so-ever. From now I am switching from Shell to Mobil 1 0W40 on the F-car as well. I realise oils do make a difference but not such a huge difference.