Chumby, some good info there on tyre sizes. That would mean the 245/75r17's are legal in QLD. For QLD at least I found the following information.
http://www.tmr.qld.gov.au/Safety/Veh...ions.aspx#50mm
This is an extract from the above re' tyre sizes;
I have been told I can put 50mm large diameter tyres on my 4WD, they do this in other states and territories, is this permitted in Queensland?
Yes, the following types of vehicles can have their tyre diameter increased by up to 50mm or reduced by no more than 26mm from any tyre diameter designated by the vehicle manufacturer for that vehicle:
4WD passenger vehicles specifically designed for off-road use (typically MC ADR category), or
4WD goods vehicles and their 2WD equivalents if the chassis and running gear are essentially the same as the 4WD versions (N ADR category)
Please note: All wheel drive(AWD) vehicles, commonly known as soft roaders,are not to be considered as one of the above mentioned vehicles.
Further information about fitting alternate tyres and rims, please refer to the Minor Modifications publication (PDF, 816 KB) and the LS section of the National Code of Practice for Light Vehicle Construction and Modification (PDF, 1.93 MB).
As a supplement, here's an extract re' maximum lifts permitted in QLD and tyre size is a part of that.
Can I raise my vehicle’s ride height?
A vehicle's ride height can be increased in a number of ways. These include:
Tyre diameter increase
Raising a vehicle's suspension
Body blocks
The limit a vehicle's ride height can be increased is dependant on which combination of the above method(s) are used. Each of the above vehicle lift methods have a maximum allowable increase they can achieve (maximum suspension lift 50mm, maximum tyre diameter increase 50mm, maximum body block lift 50mm). The maximum total combined lift of the vehicle cannot exceed 125mm.
Please be aware the maximum allowable limits specified above are not applicable to all vehicle types.
For further information about the limits and requirements for raising a vehicle's ride height, please refer to the Minor Modifications publication (PDF, 816 KB) and the LS section of the National Code of Practice for Light Vehicle Construction and Modification (PDF, 1.93 MB).
The Minor Modifications publication indicates that lifts in QLD that result from a combination of suspension/tyre/blocks up to and including 75mm do not need any certification. Lifts over 75mm up to 125mm require certification. So if I run 40mm lift plus 25mm increase radius from tyre I will not require certification.
