Thread: legal limit for tyres

as far as I am aware its a 50mm increase maximum in NSW.

If 235/70r16 are standard that equates to 735.9mm
so 245/75r 16 equates to 773.9mm
and 235 85 r16 equates to 805.9mm

so the max you could fit would be 245 /75 r16 I think

Pete.

Just to add. to work it out.

16*25.4 = 406.4mm (height of wheel)
235 is the width and the 70/85 is percentage of the width, but you have to double it

so (235*.85)*2=399.5 + (16*25.4)

= 399.5+406.4 = 805.9

In Qld it’s “No greater than 15mm increase in overall rolling diameter over the largest tyre offered by the manufacturer”. So that would rule out anything taller than 245/70R16 unless you were to have it engineered and blue plated. Qld transport used to have a brochure available with the rules laid out clearly (not sure if it is still available)

Surely RTA would have on their website and brochures in branch what is legal in NSW

I believe RTA is also 15mm and that the NCOP which states 50mm hasnt been adopted.

I thought it was 50mm over standard offered by the manufacturer in Queensland. Most manufacturers have the different tyre sizes in the manual or as in my defender on the rear wall of my cab the tyres recommended for it.
I was going to put on 235/85/16 but the topics got me thinking what is standard now as I run 7.50R16 at the moment. I better do some reserch.

Quote QLD transport current rules.

"The rim diameter may be varied from the standard size but the overall diameter of the tyre must not vary by more than +15mm or -26mm."

http://www.transport.qld.gov.au/reso..._vehicles2.pdf

As I said it's not that hard to find...

Originally Posted by philco

I thought it was 50mm over standard offered by the manufacturer in Queensland. Most manufacturers have the different tyre sizes in the manual or as in my defender on the rear wall of my cab the tyres recommended for it.
I was going to put on 235/85/16 but the topics got me thinking what is standard now as I run 7.50R16 at the moment. I better do some reserch.

Manufacturers do have different sizes listed but you will find that they all have close to the same rolling diameter.

Also you may like to check - 7.50R16 is the very close to the same height as 235/85/16 - I'm sure that is a good swap

Found this on the Queensland transport website about modifications.
The rim diameter may be varied from the standard size
but the overall diameter of the tyre must not vary by
more than +15mm or -26mm.
The maximum tyre width for a car or car derivative must
not be more than 1.3 times the vehicle manufacturer’s
widest optional tyre.
However, for an off-road passenger vehicle fitted with
front and rear beam axles, the maximum tyre width
must not be more than 1.5 times the vehicle
manufacturer’s widest optional tyre.
The nominal width of the narrowest tyre fitted to a
vehicle must not be less than 70 per cent of the nominal
width of the largest tyre fitted and never less than the
vehicle manufacturer’s narrowest optional tyre as
indicated on the manufacturer’s tyre placard.
The fitting of spacers or adaptors between wheels and
hubs, additional to those provided by the vehicle
manufacturer, is not permitted. The tyre and rim must
not foul wheel arches or suspension components under
any conditions.
Light vehicle modifications
Happy reading