Outer Limits 4x4 Board

what is the biggest tyres you can have on the road

use the edit function mate and add your state, vehicle type and year etc to your first post

will wrote:what is the biggest tyres you can have on the road

Yes, blue is my favourite colour...

Actually most states have the same rules- maximum diameter increase of only 15mm over the largest size listed on the tyre placard.

Max width will be determined by the width of your rim, clearance from the body / suspension and not going outside your guards/ flares.

murcod wrote:Actually most states have the same rules- maximum diameter increase of only 15mm over the largest size listed on the tyre placard.

Max width will be determined by the width of your rim, clearance from the body / suspension and not going outside your guards/ flares.

But larger can be engineered in places too, not like QLD

NSW now has some rule about maximum rim width being the larger of manufacturer's widest, or 8". That restricts the tyre sizes you can get away with - anybody know if an eng certificate can go beyond the 8" limit?

Scott

Scott I keep wondering about what you said with the 8" rims in NSW.... can you link me to the part of the RTA site where it says this?

I'm pretty sure an engineer will pass wider rims so long as the track width is not altered by more than 2" over standard.

When I bought my tyres from Bob Jane last week I asked about a set of new rims, and said as far as I knew 8" was as wide as I could legally go. He said what everyone seems to think- that you can go up to 10 inch if the car had 8 inch on standard, sounds like he has sold a few too.

Next time I'm talking to engineer will ask, tho won't expect a straightforward answer.

But even if 8" wide rim is maximum, there are plenty of tall tyres that will fit em. Well up to about 37" tall that I know of.

that is an interesting one. the rules definitely state nothhing wider than 8", but the RTA will always abide by the engineer's decision. I know people who have had 10" rims engineered. I have heard stories (first hand) about having wheel spacers engineered, never actually seen the paperwork though.
The RTA don't have any responsiblity to ensure a vehicle is safe/legal so once a vehicle is engineered the responsibility rests with the owner and the engineer.

and to answer the original question:

in NSW, without engineering approval, you can go 15mm up in width and diameter over the largest production tyre size for your vehicle, provided the tyre/wheel assembly does not protrude from the side of the fender. Most engineers will allow up to a 35" tyre on a full size 4WD (patrol, landcruiser, land rover, rangie etc), and smaller on smaller hardware, without changes to axles.

slosh

Try this thread - it contains a link.
http://www.outerlimits4x4.com/PHP_Modul ... 1&start=40

There is a heading a short way down on page 3:
"There are limits on the size of wheels that can be certified by a signatory.
These limits are as follows:"

At the top of page 4 it talks about 4WD vehicles.

Cheers,

Scott

slosh wrote:When I bought my tyres from Bob Jane last week I asked about a set of new rims, and said as far as I knew 8" was as wide as I could legally go. He said what everyone seems to think- that you can go up to 10 inch if the car had 8 inch on standard, sounds like he has sold a few too.

I was told by Bob Janes locally to put 265x75s on a Pathfinder, "Ive done lots of em"....

They will sell you anything to get money out of you dude... simple as that, then wipe their hands off it once you got the tires..

My neighbour has a Pathfinder and couldn't go larger than 30" because the spare won't fit. Obviously Bob's only selling 4 tyres, not 5.

Scott

Thanks for link Scott, don't know why I didn't see that b4. Oh well, looks like 8 inches is all we're gunna get in NSW. What surprised me was that passenger cars can go a fair bit wider, depending on weight on rear axle.

Also saw something else important- page 2 says if you change axles or suspension you can only fit rims with max 12.5 mm offset change from standard size for that axle. Not changing to another axle means you are allowed 25mm offset change.

will wrote:what is the biggest tyres you can have on the road

You could have a 66" tyre on the road, or 124" if you like. Not on a car of course just the tyre sitting there. There answers your question. Next.

grimbo wrote:

will wrote:what is the biggest tyres you can have on the road

You could have a 66" tyre on the road, or 124" if you like. Not on a car of course just the tyre sitting there. There answers your question. Next.

Cranky old bastard aren't you?

grimbo wrote:

will wrote:what is the biggest tyres you can have on the road

You could have a 66" tyre on the road, or 124" if you like. Not on a car of course just the tyre sitting there. There answers your question. Next.

I love seeing those 8 and 10 wheel cranes getting about .. they would have to be about a 50 inch tyre .. .. wonder what one would be like in d bush if it was stripped of all the cran gear ... keep the 10giga tonne winch though ..

Might find this interesting, from the Dept of Transport and Regoinal Services:

ADR 24 - Tyre & Rim Selection
The function of this Australian Design Rule is to specify requirements for tyres and 'Rims' appropriate to vehicle load capacity, 'Rim' size and speed characteristics.

This rule will cease to have effect from 1 January 2005.

Wonder what's in store?

can somebody use the calc. for me

need to no if 285/75R16 is within legal limits for 275/70R16.
its for a landcruiser if it makes things easier.

gettin new tyres tomorrow maybe... just cant use the calculater tonight

wow talk about a bizarre grave dig, has nothing to do with the original post. Why didn't you just start your own thread?

As to the legal limit depends what state you are, what actual model landcruiser you are talking about and its tyre placard

Spartacus wrote:can somebody use the calc. for me

need to no if 285/75R16 is within legal limits for 275/70R16.
its for a landcruiser if it makes things easier.

gettin new tyres tomorrow maybe... just cant use the calculater tonight

it will be technically illegal if 275/70 16 is what is on your tyre placard. if it's a 7x series with leaf springs the bigger tyres will hit the spring and/or the body on the front if you don't have any suspension lift. you are going from an approx 31" tyre to an approx 33" tyre.

grimbo wrote:wow talk about a bizarre grave dig, has nothing to do with the original post. Why didn't you just start your own thread?

As to the legal limit depends what state you are, what actual model landcruiser you are talking about and its tyre placard

qld
80 series
7.50R16 6plrt

further down it has:

275/70R16

really i wanted to no if 285/75 is over the allowed 15mm dia. increase
set by Qld transport.

victoria- solid axle vehicles are allowed to increase track by 50mm, and tyre diameter by 50mm over the largst tyre offered for that axle assembly. ifs vehicles are treated with greater caution..
oh...it might be more usefull to contact a state engineer.

joeblow wrote:victoria- solid axle vehicles are allowed to increase track by 50mm, and tyre diameter by 50mm over the largst tyre offered for that axle assembly. ifs vehicles are treated with greater caution..
oh...it might be more usefull to contact a state engineer.

I can vouch for that. I took my MK ute to the deni ute muster just after i finished it. Got a RWC on wednesday (VIC obviously), and got a canary on the friday by a very nice NSW policeman for having "modified track". He was trying to tell me that i had put different diffs in it, w@nker. It was cause i had mag wheels on with rediculously wide offset.

The nice fellers at a tyre shop in deni "fixed" the canary issue for me.

Coxy