Which Mobil 1 you're using? 5W-50 or 0W-40? I've started to use Mobil 1 5W-50 at 10000km service. Immediately I can feel the power of my BLM can come in more quickly and it has caused me easily rev to 4k every gear!! Anyway, after the 10000km service, it is recommended to use Fully synthetic engine oil since our service interval is 10k after that. Now I'm going to change to Mobil 1 0W-40 in the next oil change and I believe the performance would be even better in terms of lightness and power!

All the while since I've got my car since 2008 March, I've been bringing my own engine oil to SC. My SC was Juru 3S.