For a QLD engineer, QLD info needed

According to this the difference between the two is 26.5mm. The max in Qld is 15mm larger diameter than biggest factory tyre.

They would have to be pretty picky to pull you up for that considering the difference in sizes on some of our 4x4s that we get away with. However it is still illegal all the same.

Utemad is correct. Qld Transport don't want people to run larger tyres than standard, so there is no way to legally go more than 15mm larger than standard. Many people fit larger tyres anyway, many going much larger than you're proposing.

To help you make an educated decision:

Your vehicle would be technically illegal, but it will take an alert officer to notice it. The biggest factor to consider is insurance; your car is technically not roadworthy. In the event of an accident, your insurance company would need to prove that the accident could have been avoided had the vehicle not been defective i.e. you could have avoided the accident if the tyres were the correct size. They can't deny a head-on claim because one tail light was broken.

If you do go ahead, your brakes won't be as effective - make sure you use quality pads and linings (you have rear drums?)

Your speedo measurements don't sound right; have you got those figures the right way around? I would expect 100 on your speedo to be 91 on the GPS. Changing to the tyres you want would bring the true 91 up to about a true 98.

The size you're interested in is the most popular size of 4wd tyre in rural Australia - you'll be able to find a replacement the right size just about anywhere they sell tyres. You will have a much larger selection of tyres too, almost all with higher load rating than the factory tyres (and therefore tougher, and less likely to fail.)

Taller gearing will affect your low-speed off-road capability, and you'll probably use more fuel because the larger and heavier tyres are harder to turn.

That's all I can think of for now.

Cheers,

Scott

I changed my 96 GLX pajero over from 235/75/15 to 235/85/16, that is from 29" to 32".

Went to a local mechanic in brisbane for a modification plate.
We talked it through, but I had a few facts and figures with me.
Other model pajeros at the time had larger tyres (e.g. GLS/Exceed) and the same mechanicals in regard to brakes etc.
Also, I was keeping to 235 wide tyres, and same offset rims (15x6 to 16x6) so no change in track.
I am told I was lucky to get it through.

Speedo now reads 100 at 102k true.
Do some research on other models, even one of different years but same mechanicals like brakes and suspension. You might only be going up 15mm after all :-).