Why are Australian petrol prices so high ?  

Gav, this is a hoary old chestnut. The pricing model that drives local pump prices is freely available information - look on the Caltex website and other places.

I keep my own spreadsheet version that says our pump price should be around $1.32/litre today based on $US1.05/$A exchange rate and MOPS95 unleaded at US$120/barrel. This year's pump price peaked at $1.45/litre in the first week of May when MOPS95 hit US$138/barrel.

In comparison our pump price was $1.55 - $1.60 back in July-Aug 08 when global oil prices were at record highs and the A$ was tumbling due to the financial crisis.

Our pump pricing is based on Singapore refined product prices (MOPS95 unleaded) because most of the petrol we buy is shipped as finished product from Singapore.

We are incredibly lucky to have been shielded from the recent run-up in global oil prices by the parallel run-up in the A$. How much longer will that happy situation last?
Cheers, Mark

Well - the pump price I paid yesterday was $1.42 (for petrol with 10% ethanol) so if the price should be $1.32 then I guess my impression its overpriced compared to last time round is right - though its "only" 10% rather than the 25% I would have guessed.

Could you upload your spreadsheet to Google Docs and make it public ? Would be interesting to have the data to hand :-)

Cheers,
Gav.