Outer Limits 4x4 Board

I am as frustrated as you and we are both stuck in Brissy (QLD) rules!!!
I am wanting 33" on my FJ40 rather than the 32 or 31" which are more common size (undersized for the 40 series)

Well all i need to know is what is the overall dimension and what they use to determine this and then if then use the tyre and rim guide to decide or the actual factory measurements.

My two options are
32x11.5x15 buckshots but the are a small 32+ they have an old tread pattern + they will look shit on my car with the 100mm extended flairs.

33x12.5x15 Bighorns 30 bucks more than buckshots but have a new tread pattern with better sidewall construction. They are a big 33 too and will look great its just weather they are legal.

I really want some1 to say yes or no.

What we need is a proof that we can printout and leave in our car to show a cop or for insurance, registration purposes.

I thought one guy here won a case regarding 33" tyres

Yer he did i went to his shop today and got that print out. He said that according to those specs if legal to run the 33's but i just spoke to the inspector for qld transport and he said that they only use the rim and tyre association manual to determine the size. The guy at the shop used a universal tyre manual so im not sure if its Australian standard. The only thing stopping me from putting 33's on is that if you get cought and they did defect ur car even after showing the paperwork is u loose points. and atm i am on a good driver scheme so 1 point for a year.

another thing was the guy won the case for the 33's on the fj40 but they never said it was legal!! lol

Im more worried if I have an accident and the insurance wont cover!

We need someone whos got a copy of that rim and tyre association manual and give us a copy or scan it.

no one else here seems to be posting on this thread...

i just spoke to a guy and he said that he can put a mod plate on the car saying that becuase i have upgraded the front brakes to discs that the tyre size needs to be increased haha. he said he can go up to 2" bigger!

Midnight Middy wrote:i just spoke to a guy and he said that he can put a mod plate on the car saying that becuase i have upgraded the front brakes to discs that the tyre size needs to be increased haha. he said he can go up to 2" bigger!

he's full of crap.

there is no mod code for increased tyre size.

Which engineer is that? I need his contact number so I can get it mod plated, how much did he say to do the mod plate?PM his contact details please. I have disc brakes and 351 on mine all legal and mod plated
But QLD Transport has a strict law on 15mm max

how do you calculate or convert 7.5 x 16?

been searching online and the formula Im getting is 2 x 7.5 + 16 = 31"
or 762mm in Diametre?

is there a cheap 32x12.5x15???

c110gtr wrote:how do you calculate or convert 7.5 x 16?

been searching online and the formula Im getting is 2 x 7.5 + 16 = 31"
or 762mm in Diametre?

7.5 is the sidewall and the width.

so 2 x 7.5+16 = 31 = 762mm.

BUT, as with all things in this world, just because they say they are 7.5R16LT does not mean thats thier size lol.

Also, an upper limit must be set so that vehicle designers know the maximum size they can expect to see that tyre from any tyre manufacturer.

for instance, lets say for some reason a crane is designed and specs 7.50R16LT, they design it for 762 mm, but a tyre of 819mm gets put on when they wear out. Now the tyre rubs on the guard, causes a blow out, millions of people die, the earths inner core stops rotating.

Solve this by having an oprganisation, specify standards. The tyre and rim association manual says a 7.50R16LT cannot be bigger than 819mm.

Now the crane designer must design his wheel arches and suspension around an 819mm tyre, and the world lives on.

Who can we get a soild answer from?
Is the rim and tyre assiciation the legal book they use or is there another one?