Just A Question

[Dahtone Racing]

read the rta guidelines again guys

legal is 10mm larger for the whole wheel and tyre package

[scathing]

If you read the .pdf file posted above it says that over 1201kg year models after 1973 i think then you can increas it by 2" there for on a Skyline you should be abel to run 18's legally.

Can you read the PDF file again and tell me where?

And please, read it carefully and the text around it just so you get the context right.

Edited July 11, 2006 by scathing

[Michael_1882]

Scathing ok i've read the whole section on wheels it's all kinda comfusing. What did you conclude?

[scathing]

My conclusions on the diameter permitted can be found here.

As for the table you're referring to (the "1201kg year models after 1973" thing), that's the maximum width allowed with an engineer's certificate for a car.

You can go to a 26mm (1") wider rim than the biggest wheel on your tyre placard without an engineer's cert for cars weighing over 1200kg past 1973, when the relevant ADR was introduced.

Note that the width increase permitted (with and without the cert) is not based on what came with your car. Its based on the biggest wheel the tyre placard (which would be the biggest wheel the OEM offers as an option for your vehicle).

So, if you had a frontal lobotomy and bought a new Commodore Executive, you can go 1" wider than the SS Commodore's rim (which is the widest OEM rim that is listed on a Commodore's placard).

[mr 32]

As for diameter / circumference, this is what the VSI06 you linked to (which I assume you read before linking to it) has to say:

Correct me if my interpretation is wrong, but when the RTA says that the diameter measured is the "wheel and tyre combination", they're not just looking at the increase in rim height to determine its legality.

read the rta guidelines again guys

legal is 10mm larger for the whole wheel and tyre package

2gu up an scathing are on the money

[d00dz]

Well you learn something everyday.

Time for some new 20" chr0mes. YEA BABY! Tempe tyres here I come!

[mr 32]

Well you learn something everyday.

Time for some new 20" chr0mes. YEA BABY! Tempe tyres here I come!

do it

[Michael_1882]

My conclusions on the diameter permitted can be found here.

As for the table you're referring to (the "1201kg year models after 1973" thing), that's the maximum width allowed with an engineer's certificate for a car.

You can go to a 26mm (1") wider rim than the biggest wheel on your tyre placard without an engineer's cert for cars weighing over 1200kg past 1973, when the relevant ADR was introduced.

Note that the width increase permitted (with and without the cert) is not based on what came with your car. Its based on the biggest wheel the tyre placard (which would be the biggest wheel the OEM offers as an option for your vehicle).

So, if you had a frontal lobotomy and bought a new Commodore Executive, you can go 1" wider than the SS Commodore's rim (which is the widest OEM rim that is listed on a Commodore's placard).

Thanks that makes sense. So teh biggest OEM wheel offered by nissan for the R33 woudl be??????? 16'??

[scathing]

Thanks that makes sense. So teh biggest OEM wheel offered by nissan for the R33 woudl be??????? 16'??

No idea, mate.

If you've got one, locate your tyre placard or owner's manual. It should be printed in there.

The standard R33 GTSt / Maxima / S14 200SX rim is 16x6.5, and I don't know if they had an optionally larger rim, so on the safe side I'd stick to a 7.5" wide rim unless you can find "official" documentation saying the car came with something bigger.

N.B. This interpretation of the ADR is not national, so this is strictly a NSW-only thing. VicRoads says that you can go 1" wider than the widest rim for any model using that chassis without an engineer's cert, regardless of if its on the tyre placard or not. So from my Commodore example, you could go 1" wider than the rim on a HSV Clubsport R8 while still remaining legal in Victoria.

I point that out just in case you ask in the "Suspension, braking and tyres" forum and some Victorian tells you that you can go 1" wider than the 17x9 that comes on a GT-R (assuming the two share the same chassis, which is another thing I don't know but I'd hazard a guess at). If my assumption about the GTSt and GT-R chassis is accurate it would be legal for them, but its not for you unless the tyre placard for the GTS-t has the rims for the GT-R.

Before anyone asks, I'm not 100% sure if VicRoads has a rule on the diameter of the wheel (in case someone replies back telling us there's a only 1" diameter increase permitted on the rim). I'm only aware of the differing width rules between states because of an article in a Hot Tuner edition of Motor Magazine which pointed it out.