And don't forget "model" isn't "trim level". If you care about this stuff, you might want to call the RMS's expert-line people.
Last time I asked the question, you could fit wheels to your Commodore Executive, without any certification or engineering, that were 1" wider than what HSV fitted to a GTS. Because HSV's are just Commodores, with the same suspension geometry & wheel arches etc.
The wording of that Vehicle Standards Information bulletin was exactly the same with respect to vehicle-model & sizing as the wording in the VSI that Skylarking just posted. However, the bulletin I was using back then was from 2003, this has been replaced by the one from 2019 that Skylarking referenced (and yet the wording regarding sizes is the same).
So ... if you care, I think it's worth getting clarity from the RMS's experts (not the nice lady behind the counter at the local RMS office - they used to have a 'phone number you could call for such things in order to get someone with a clue, and surely they must still have?).
The document i linked above seems outdated and will likely be revised again. For example, it states
- You must not fit wheels with rim widths less than the minimum width fitted by the vehicle manufacturer for the particular model.
Because of the stricter interpretation of model as “model variant”, I can’t replace the wider rear “staggered“ wheels to match the narrower fronts... The point is clarified in part by the fact that even the spare wheel which is exactly the same as the front wheels has a “temporary use” or “temporary wheel” sticker on it.
Today’s regulator and compliance terminology revolves around “model variant” which sadly isn’t the same as the older term “model”. Don’t get me started how one can write “model” in a document and then interpret it differently and in a much narrower sense, it’s just bureaucratic lunacy and stupidity really.
As is, in my case this “model variant” interpretation means an SS is different from an SSVRedline
If model variant was interpreted the same as model was in the past, then it wouldn’t be an issue swapping any wheels available in the broader VF range, whether it’s wider or narrower... but I can’t,... Holden said I can’t,... DOTARS technical group said I can’t,... rego authorities also said I can’t... Haven’t talked to a certifying engineer but it shouldn’t be needed if things were logical.
Regulators said it was more complicated because of ABS/EBD/ESC but Holden could update the RVD and be done with it... Dealing with Holden was very frustrating as they said it was bla bla bla engineering bla bla bla and just wanted to fob me off, then when pushed all they DOD is provide a letter to state I can install 19” staggered rims... idiots...
End result of this dive down the rabbit hole was that I’d have to talk to an engineer and get them to “engineer“ the narrower standard SS wheels by presumably taking my car out for a fang after I hand over a wad of cash.