ESC vehicles can have a 50mm lift of either tyres, suspension or blocks but not a combination thereof before needing to be assessed and certified. Well for any state signed up to the NCOP which is most of them.
No not in Qld, this is where the confusion is coming in because they are now referring to the Qld code of practice instead of the national code. It's all in the wording a vehicle without VSC is considered a vehicle lift, a vehicle with VSC its called a suspension lift and larger tyres would require engineer approval.
The following information provides some general guidance about raising a vehicle’s height
Without ESC-
A vehicle lift up to and including 75mm combining both suspension lift and tyre diameter increase (maximum suspension lift 50mm, maximum tyre diameter increase 50mm) is acceptable under self-certification.
A vehicle lift between 76mm and 125mm inclusive, combining a suspension lift, a tyre diameter increase and a body lift (maximum suspension lift 50mm, maximum tyre diameter increase 50mm, maximum body lift 50mm) requires certification and testing by an Approved Person.
With ESC
A suspension lift up to and including 50mm is acceptable under self-certification. A vehicle lift over 50 mm or due to a combination of any other lift (tyres, or body blocks) requires certification and testing by an Approved Person.
I don't believe it has anything to do with the height of the vehicle but more the operation of the VSC as VSC work by applying brake pressure to the wheel that requires it, obviously if you go changing the rolling diameter of the wheel more braking force will be required to stop it but the VSC computer is not smart enough to recognise this on the operation of the VSC will be hampered.
The whole thing has been poorly handled but with Xmas parties fast approaching some departments obviously need a it of extra revenue.