Quote:
Originally Posted by D3Jon
So what's the legality of an 85mm overall vehicle lift? (35mm from Kieren's new tyres + the original 50mm suspension lift).
I can't seem to find anything definite for WA on here: Vehicle modifications
Jon |
I would think the lift is OK, but the 71mm increase in tyre rolling diameter is definitely not legal. 71mm that’s 9.6%, so the speedo is 9.6% out and (the main reason why it’s not legal) the brakes are now 9.6% less effective than designed.
The "New" rules that have been mentioned lately here are as follows;
Quote from the National Code of Practice for Light Vehicle Construction and Modification (NCOP)
OVERALL DIAMETER
The overall diameter of any tyre fitted to an off-road passenger vehicle or a commercial vehicle must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the vehicle manufacturer for that model.
So these tyres are not legal under the NCOP. But wait there more…
"Please be aware that the NCOP only represents the technical requirements that must be met - administrative requirements are dealt with separately by each state and territory's administrative guidelines or business rules."
What this means is that ALL vehicles in the country must meet this as a minimum, and the State authority cannot introduce a rule that is outside these rules. It also means that the state can have their own laws that are tighter than these. I know that QLD, NSW and VIC are all currently specifying max of 15mm.
The NCOP also talks about speedo accuracy, and that when larger tyres are fitted the speedo MUST still comply with ADR18 (instrumentation). This ADR is full of mathematical equations but the simplest point (which is now failed) is:
5.3. The speed indicated shall not be less than the true speed of the vehicle
This is why most new cars display a higher speed than what you're actually travelling.
No mater what WAs state law is this doesn’t meet the new national laws…. So in the event of a good prang - I think you'll be on your own