Rod replied:

Colin, you could do what I've done and that is actually state the size of your tyres on your insurance application. My money's been accepted. As for Cooper tyres read the fine print, one little nic and your guaranttee's blown.

Mike replied:

Colin, save yourself the hassles and fit BFG A/Ts as they are available in standard Jackaroo size. I've had them on mine for about 52000kms and couldn't be happier. They've done very well on Simpson sand, Birdsville Track & Mungo mud, Pedirka track & Flinders rocks and the Victorian High country. No Punctures yet and wearing really well. Happy trails, Mike.

Grant replied:

Colin, spoke to my local tyre dealer about the exact same thing yesterday and he said "what's it say on your tyre placard? No can do because they (insurance companies) can come back at us (tyre dealer) and sue us for fitting an illegal tyre."
So tyre dealers are protecting their own arses, and fair enough, but not trying very hard to be helpful. So I spoke to my insurance rep this morning and quizzed him and basically it comes down to the Load Ratings and Speed Ratings. If you are on or above the trye placards minimum requirements on these you should be ok. They are mainly concerned about a cheap tyre that doesn't meet the placard in the above two areas, therefore making it unsafe if loaded up or going too fast. To Rod, at least Coopers offer a guarantee of sorts so they must be fairly confident they wear reasonably well. Do BFG A/T owners feel so threatened by the Cooper S/T's that at every opportunity on this and other forums they feel the need to bag them. Give the S/T's a couple of years to either prove themselves or fail. Time will tell. Colin, as Rod rightly said, state your tyre size on your insurance application and if they take your money, then they have no comeback. Steven P has a Jack with 245/75's on in Vic, he may read this and let you know his experience.

Grant replied:

Colin, spoke to my local tyre dealer about the exact same thing yesterday and he said "what's it say on your tyre placard? No can do because they (insurance companies) can come back at us (tyre dealer) and sue us for fitting an illegal tyre."
So tyre dealers are protecting their own arses, and fair enough, but not trying very hard to be helpful. So I spoke to my insurance rep this morning and quizzed him and basically it comes down to the Load Ratings and Speed Ratings. If you are on or above the trye placards minimum requirements on these you should be ok. They are mainly concerned about a cheap tyre that doesn't meet the placard in the above two areas, therefore making it unsafe if loaded up or going too fast. To Rod, at least Coopers offer a guarantee of sorts so they must be fairly confident they wear reasonably well. Do BFG A/T owners feel so threatened by the Cooper S/T's that at every opportunity on this and other forums they feel the need to bag them. Give the S/T's a couple of years to either prove themselves or fail. Time will tell. Colin, as Rod rightly said, state your tyre size on your insurance application and if they take your money, then they have no comeback. Steven P has a Jack with 245/75's on in Vic, he may read this and let you know his experience.

Grant replied:

Colin, spoke to my local tyre dealer about the exact same thing yesterday and he said "what's it say on your tyre placard? No can do because they (insurance companies) can come back at us (tyre dealer) and sue us for fitting an illegal tyre."
So tyre dealers are protecting their own arses, and fair enough, but not trying very hard to be helpful. So I spoke to my insurance rep this morning and quizzed him and basically it comes down to the Load Ratings and Speed Ratings. If you are on or above the trye placards minimum requirements on these you should be ok. They are mainly concerned about a cheap tyre that doesn't meet the placard in the above two areas, therefore making it unsafe if loaded up or going too fast. To Rod, at least Coopers offer a guarantee of sorts so they must be fairly confident they wear reasonably well. Do BFG A/T owners feel so threatened by the Cooper S/T's that at every opportunity on this and other forums they feel the need to bag them. Give the S/T's a couple of years to either prove themselves or fail. Time will tell. Colin, as Rod rightly said, state your tyre size on your insurance application and if they take your money, then they have no comeback. Steven P has a Jack with 245/75's on in Vic, he may read this and let you know his experience.

Rob replied:

I was doing a bit of digging about modiforcations a while back. I do not know which state you are in, but the NSW RTA has a webpage that covers this issue at http://www.rta.nsw.gov.au/manuals/registration/lvm/lvmfrm.htm
The information about wheel size is at http://www.rta.nsw.gov.au/manuals/registration/lvm/lvmfrm.htm & I should imagine that the insurance companies would comply with this law.

Eli replied:

Hi Col
I’m trying to find a way to replace my 100 Series Landcruiser’s original 265/70/16 tyres with a larger 275/75/16 (52 MM extra in diameter), and stay legal.
I wouldn’t like to spoil your day but I was researching the RTA regulations for a few months (including a few phone calls to their technical department) and I couldn’t fined a way around the paragraph stating:
“For a minor modification (owner certified), the overall diameter of the alternative wheel and tyre must not be greater than 15mm over the largest diameter wheel and tyre specified for the vehicle and shall not be more than 15mm below the smallest diameter wheel and tyre specified for the vehicle” You can find it at the RTA web site that Rob referred you to (3.8.3 Certification of replacement wheels and tyres).
I will be happy to hear if you or anybody else found a way around that part of the regulations.
Thanks Eli

Eli replied:

Hi Col
I’m trying to find a way to replace my 100 Series Landcruiser’s original 265/70/16 tyres with a larger 275/75/16 (52 MM extra in diameter) and stay legal.
I wouldn’t like to spoil your day but I was researching the RTA regulations for a few months (including a few phone calls to their technical department) and I couldn’t fined a way around the paragraph stating:
“For a minor modification (owner certified), the overall diameter of the alternative wheel and tyre must not be greater than 15mm over the largest diameter wheel and tyre specified for the vehicle and shall not be more than 15mm below the smallest diameter wheel and tyre specified for the vehicle” You can find it at the RTA web site that Rob referred you to (3.8.3 Certification of replacement wheels and tyres).
I will be happy to hear if you or anybody else will find a way around that part of the regulations.
Thanks Eli