ok so it can be established that if your tyre placard states 15" rims then you can legally fit 17" rims

but i was looking in my owners manual and i noticed that whilst the exec has 15" rims the magna V6Si/verada have 16" rims

so if the V6Si/verada has the same suspension etc. then could an magna exec then be "legally" fitted with 18" rims..... or is it too hard to explain to the authorities?

find a placard that has 16" rims on it
illegal i know

Better still vrx placard.......19" rims legally

ooo I didnt even think about checking the placecard when I got my rims! My car came with 16" stockies anyway so I think my 18's should be fine?....*Crosses fingers* The cops wouldnt seriously pull you over and check your placecard would they?!

No the cops would just defect you then you have to pay an engineer $400 to check your placard

i'm more interested in the legal loop hole than to fit another placard
but still the question remains..... what is the difference between the exec and the V6Si/Verada that makes it "illegal" to fit 18's on said exec but not said V6Si/Verada

Hmm this has been covered hundreds of times before and the final consensus after checking through each state's legislations is that as long as the rolling diameter of the wheel remains within a certain tolerance (some small percentage) to keep the speedo reading correctly. You have to also check your offset and tyre width so you aren't increasing or decreasing your vehicle track by a greater amount than the allowed percentage (much like your rolling diameter). New tyres for your rims should also maintain or exceed the load rating required for your car. This is most certainly the case in QLD and I'm positive the other states are the same too.

Do a search.

Im with Lucifer, im positive if the overall rolling diameter does not change by more than 15mm (i think) then you are fine

yeah finally found it on the dpi wa website

overall diameter must be similar so as to keep the speedo accurate
speed and load ratings must be equivalent or better
track must not be greater by 1" or lesser
rim width not to exceed 7"

well my rims standard are 16 inch rims, and i have 18 inch rims, but apparently the rolling diameter is 3mm to big, so technically that rule doesnt always apply.

i just plugged in some figure on a tyre calculator and 205/65R15 = 235/40R18 at -.39% diameter
i like the look of the ROH Prowler Black

http://www.dpi.wa.gov.au/licensing/1884.asp


The fitment of so called "plus one" and "plus two" and tyres is acceptable providing :

the overall diameter of the large rims fitted with the lower profile tyres do not exceed the overall diameter
all tyres and rims fitted to the vehicle are of the same size and profile

W.A. is a little more restrictive than NSW - W.A. can't increase the size of the overall diameter, but NSW can go +or- 15mm.
Also, WA restrict to 7" or factory wheel width, factory +1" is OK as long as it's no more than 7" wide. That rules out MANY wheel options. Ouch.
So if you're in W.A. and your tyre placard only shows 15" rims, you can only go "plus 2" to 17" rims.