Thread: 17" on 3.0 D4 legal in NSW due to placard

And of course you have that in writing. They are notorious for giving incorrect information.

Garry

I would also hate to test that in an insurance claim......

If I was to get serious about going down that path, I'd get written confirmation from the RTA. I'd also consult my insurer to find out what they thought about it.

I'm still hoping for 18" rims.

If you fit smaller brakes to a D4 then I suspect you also need to recalibrate the computers.

When the computer decides a little braking is in order it will activate the brakes on a given wheel with a certain amount of brake pressure for a certain amount of time. Being a 3.0, it will assume the 3.0 brakes are fitted. If the smaller brakes are fitted then it'll send the same brake signal but the actual braking effect will be less as the brakes are less effective. This is not dissimilar to the effect of fitting much larger and heavier tyres.

Thus, this brake mod will throw out the CBC, ABS, ESC, EBA, EBD, ETC and TSC, all of which rely on computer-controlled brakes.

Now the logic above may be wrong and the 2.7 brakes react precisely the same as the 3.0 -- but then why are they different sizes. Only LR engineers could tell us, not the RTA. So I suspect there is a difference. The next question is the magnitude of the change, which is unknown to me, and I'd be quite suprised if it were known to the RTA, therefore I am surprised they are prepared to state so categorically this mod is ok.

Perhaps you could put this to the RTA person. I will be very interested to hear his response.

Maybe also mention that manufacturers are typically lazy and use just the one placard for all vehicle models irrespective of the rim or tyre sizes that will fit. As we know, 17s physically do not fit on the 3.0. With sophsicated vehicles like the D4 the days of just slapping on different bits and pieces then calling it good are over.

As Land Rover did not intend 17s to be fitted to the D4 any fitting of smaller brakes is likely to cause warranty issues.

The smaller brakes will not be unable to stop the vehicle by any means. There are specific braking tests which need to be done in a variety of configurations and if the brakes can stop a 2.7 to that effect they can certainly stop a 3.0 as they are the same GVM or close enough.

You'd definitely need to notify your insurer.

ohhh not quite...... (well at least under QLD regs)


if your vehicle was provided with rotors and calipers of size X then you cant go down to size W so you can fit the smaller rims without a re-engineer... you can go up to size y without it becuase you havent decreased the overall available braking ability.

if it came from factory with the 17 inch brake set then your laughing.

personally Im of the opinion that ANY brake mods should require at least a certified technical review

yes....perhaps a less involved option to pursue the special 18" wheels gghaggis was investigating.

dumb question

why the **** would ANYONE ever even consider REDUCING the BRAKING ability of thier vehicle?

ffs, if you dont want to wreck your 18"s by going off road, get something that doesnt need big wheels with licorice strip tyres

Originally Posted by Sprint

dumb question

why the **** would ANYONE ever even consider REDUCING the BRAKING ability of thier vehicle?

ffs, if you dont want to wreck your 18"s by going off road, get something that doesnt need big wheels with licorice strip tyres

ageed tho with a few buts???