what is legal

[smerfster Lurker Find all posts View Profile Close smerfster]

what is legal

So time to replace the gradtreks is fast approaching after a bit less than 40,000k's

A quick read of these forums shows that in parts of the country, the max legal size increase is 15 mm

The Prado is supplied with dunlop AT 20 265/65R17. These have an outside diameter of 30.6 inches, with converts to about 777mm. Adding 15mm to these gives 792mm

I want (as do many) to go up as big as possible while staying within the legal limits.

For this reason I have been looking at 275/65R17 tyres.

yoko go12's are 795mm od
bfg are 792 mm od
d694 are 790 mm od

If we go by the actual size of the original tyres then the bfg and d694's are ok, but the yoko go12 is not (by about 3mm).

Is there a Standard Size for tyres ? or must we take the outside diameter of the grandtreks ?
Is any 275/65R17 ok ?
Are all 265/70R17 illegal ?

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

Re: what is legal

Smerf being discussed a 100 times before I suggest you read previous threads as their is a wealth of info and it cover NSW regs. And or use search function.

[JoshF Advanced Member Find all posts View Profile Close JoshF]

Re: what is legal

What did your research with the RTA uncover? In QLD the transport department publishes a guide to mods which covers tyre size changes.

[OldGreyGuy Senior Member Find all posts View Profile Close OldGreyGuy]

Re: what is legal

In QLD the transport department publishes a guide to mods which covers tyre size changes.

That would be the Light Vehicle Modifications Booklet.

I am sure that the RTA or VicRoads, etc, have ones available on their websites in each state.

[smerfster Lurker Find all posts View Profile Close smerfster]

Re: what is legal

so for NSW
I think the relevant info is in two guides is

Vehicle Standards
Information Sheet No. 9 Guidelines for alternative wheels & tyre
http://www.rta.nsw.gov.au/registrati...vsi09_rev4.pdf

from the guide

Minor changes to wheels
Wheels up to 26mm wider than the largest optional wheel recommended by the vehicle manufacturer for the
vehicle can be fitted without the need to notify the RTA.
The outside diameter of the wheel and tyre combination must be no more than 15mm over the largest diameter
wheel and tyre combination specified for the vehicle and not more than 15mm below the smallest diameter wheel
and tyre combination specified for the vehicle.

I have noticed that some people are referencing the

National Code of Practice for light vehicle modifications
http://www.infrastructure.gov.au/roa...g_3Feb2006.pdf

OVERALL DIAMETER
The overall diameter of any tyre fitted to a passenger car or passenger car derivative must not
be more than 15mm larger or 26mm smaller than that of any tyre designated by the vehicle
manufacturer for that model.
The overall diameter of any tyre fitted to an off-road passenger vehicle or a commercial vehicle
must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the
vehicle manufacturer for that model.
Speedometer accuracy must be maintained for the selected tyre and rim combination to within
the degree of accuracy specified in ADR 18 where applicable.

but I think that for NSW at least the regulations are listed in
Guidelines for light vehicle modifications
http://www.rta.nsw.gov.au/registrati...s_nov_2007.pdf

This references the first guide that I listed.

Anyone think this is not correct for NSW ?

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

Re: what is legal

Northern Territory is the same for Tires