Correction:The current petrol/diesel excise is 42.7c/litreAdd to...

Correction:
The current petrol/diesel excise is 42.7c/litre
Add to that say 12c/litre GST (@ say 1.40/litre at the bowser)
which gives a total tax charge of 54.7c/litre

https://www.aaa.asn.au/fuel-excise-explained/:

For a car traveling 20,000 ks P/A the EV 2.5c/km would pan out at $500/yr
While an ICE traveling the same distance would pay a combined excise/GST of $765 (at say 7 litres/100 kms)

IMO, this introduces another variable into the economic mix of comparing EVs to ICE vehicles.
The capital costs, depreciation , & replacement battery costs have been stumbling blocks for EVs
in the past and the prospect of a road tax only exacerbates the economic argument for EVs, IMO.

Where are you at bluesumuari ?