Answering a few open questions -
1. Yes Oil changed with the service. As synthetic was 2.5 times as costly as unbranded mineral, I chose mineral.
2. Yes they got the tyre pressure down to 32 (habit slaves!) I insisted and made them take it back to the compressor and filled it back up to 50. Lots of weird glances endured... I check and top up regularly at each weekend using a digital gauge and battery operated pump.
3. AC use was not significant. It was only two / three instances, each not lasting 5 minutes before I got nervous about the FE hit and switched to window cracks.
4. I P&G regularly since Dec 08, (when I got to know about it on joining ecomodder). The change I had with the octane change was switching from granny mode to jackrabbit mode for my acceleration, on reading about the ABA testing done by SVOboy.
5. My car is almost identical to FIT (same platform), has 1.5L 5MT IDSI engine (not the popular Vtec variety), and does not require premium fuel. the premium fuel was touted to make the vehicle run smoother, so was using it.
Unchosen: What is the diagnostic unit you are talking about?
aerohead: Is the knocking thing equivalent to lugging?