The oil consumption issue with the Si was discussed A LOT during the first year or so after the car came to market (Dec '05). Numerous owners here, at ToV, FGCoupe, etc. reported oil consumption issues prior to their first oil change. With feedback and history from the RSX groups, this was put down to 'normal for this car', more so with higher, extended use of hi-RPMs.
As to "real-world' oil life, the only method that gives a 'for certain' answer is a UOA with TBN. As many owners are put off by the cost and inconvenience of actually doing so, all the net speculation continues... That is too bad as that little bit of cost and effort can show you more than your oil life, it can actually be used to detect certain internal engine issues well before they would normally become apparent through normal driving.
And if you are a stats nerd, it helps control the OCD
