Tyre placard - 255's might be legal? (NSW)

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

I've always held off from buying 255 width tyres, as the RTA rules forbid reduction of tyre width, regardless of an engineers advice. However, my placard lists both the 215's and the 265 tyres, on each rim respectively (6" and 7"). So I'm thinking I'm legally allowed to to go any width between 215 and 265 (given load and speed ratings are ok).

Any thoughts on this?

Tyres listed:
215/80 16x6 107s
265/70 16x7 112s

I rang RTA technical, and he said it's fine!! I'm just concerned another RTA officer might have a different opinion (AUVIS).

[rags Advanced Member Find all posts View Profile Close rags]

Glen
When i had my old 90s it was a RV6,I replaced the 16x6 rims with 16x7 kimberley mags and onto these i always ran 245x70x16 tyres as this maintained the original rolling diameter.The advice i also received was the same as you,due to the fact that it had the dual tyre placard and they fitted into the range between the 2 sizes .I never struck any issues so was never challenged about if it was legal
Russ

[ianafloat Junior Member Find all posts View Profile Close ianafloat]

Although this is only my understanding, I would agree that the if the rolling diameter is the same and you don't go too narrow for the rim which you are not, I can't see how it would be challenged.

[Guest Close Guest]

What is confusing here with the tyre placard is the load rating. If you choose to go between 215 and 265 in width but still maintain the same overall diameter, what is the minimum load rating you are supposed to meet?

[rags Advanced Member Find all posts View Profile Close rags]

When referring to the overall rolling dia ,i was referring to maintaining it for correct speedo readings and diff ratio being maintained ,this more a personal thing rather than a legal requirement. I was not inferring that was part of the qualification.My understanding was that you cannot reduce the load rating so with the BF gs in a 245 the rating was 109s i think.So if a GXL had 265s with a 112 loadrating then if reduced in size then it should also be a 112 load rating. Then there is the issue of speed rating but my understanding was that it can be reduced to an equal to 140km rating whatever that is.

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Good points about the load rating, the officials are very particular about that. I'll just work off the higher figure (112) and it'll be fine.

rags is also correct about the speed ratings, a lower rating is fine as long as it's no lower than 140km/h, which I believe is "N".

My engineer says the narrower width is okay, given what's on the placard. He'll just need to cert the height...

BFG M/T KM2, 255/85R15 119Q (3 ply)
Actual OD is either 33.1" or 33.3", there seems to be different specs, different versions of KM2.