Largest standard tyres on DII in the world - eg on G4

[ozscott]

Hi all. Unless and until Qld adopts the current Australian Code of Practice for mods including tyre sizes for genuine 4wd vehicles, currently anyone with 265/70/16 and above are technically illegal in Qld..having said that that tyre looks good and does not look oversize. The TORUM that covers it does not refer to the tyre placard that I can see and refers to no more than 15mm over the largest standard size by the manufacturer....does that mean in the world...arguably. So, I reckon from memory that the G4 Disco IIs ran a 75 profile tyre that was still about 235/245 wide...does anyone know the specs or can refer me to a site that contains same.

Cheers

[Slunnie]

I'm not sure, but it was probably whatever was fitted to the Bowler Wildcat which runs D2 axles.

[Graeme]

They ran LT225/75 MTRs, in Aus at least - just very slightly larger than the 235/70s.

[Slunnie]

Are you sure? They look a lot bigger than that to me...

http://es.motorfull.com/wp-content/uploads/2006/12/bowler-wildcat-2.jpg

[Graeme]

Are you sure? They look a lot bigger than that to me...
I know I don't wear glass if I can get away with it, but that doesn't look like a D2 to me!

I used to have a magazine with a couple of pics of the G4 D2s from which I determined that they had to be 225s - not big or wide enough to be 245s.

[Slunnie]

As I understand it, the rule relates to the axle, so if you run LandCruiser axles you can run 31's, if you run Unimog axles you can run 44's etc, but it needs to be the largest for the axle. AFAIK thats why there was some excitement over a factory build by Toyota I think it was of a big tyred Prado or something for Iceland. The Bowler Wildcat uses Disco2 axles.

[Chucaro]

Anderson's @ Hervy bay have a Dakar-Bush rangie on a Disco chassis with very large tyres and is legal in Qld.

[dmdigital]

Try this information, used to be on the old Disco2 web site.

Discovery 2 - Tyre Sizes (http://www.clifton.nl/index.html'tyresizes.html)

[ozscott]

Thanks fellas. Unfortunately in Qld its based on the largest size as fitted by the manufacturer on the particular vehicle being assessed - ie not on axles manufactured by the manufacturer; at moment no larger than 15mm above the max size as standard...unless and until the uniform code which currently is up to 50mm greater rolling diameter.

Cheers

[Slunnie]

Sounds like you've answered the question yourself then. Whats on the placard.

[ozscott]

Not really Slunnie, because the largest on the placard is 235/70/16, but the legislation in Qld does not use that as the reference point, it just uses the largest by the manufacturer with that vehicle, so if LR equip the G4 (assuming that they do, which I think is well arguable) and IF they were for eg 235/75/16 we would be home and hosed in Qld with 265/70/16 for example.

Cheers

[sniegy]

I am pretty sure the placard has 4 sizes from memory..
235/70/16 (16" x 7")
255/65/16 (16" x 8")
255/55/18 (18" x 8")
& the last one i cant seem to remember, but i am sure there was another, which may be what Graeme said 225/70!? but cant recall.
Cheers

[Slunnie]

You guys have it tough up there! Its off the standard size for diameter.
http://www.transport.qld.gov.au/resources/file/ebde8d0521b67c6/Pdf_modification_motor_vehicles2.pdf
Pg11




The rim diameter may be varied from the standard size
but the overall diameter of the tyre must not vary by
more than +15mm or -26mm.

[Graeme]

The 4th listed size is 215/75-16, but MTRs weren't made in that size, with 225/75-16 being the closest.

[Tombie]

Not really Slunnie, because the largest on the placard is 235/70/16, but the legislation in Qld does not use that as the reference point, it just uses the largest by the manufacturer with that vehicle, so if LR equip the G4 (assuming that they do, which I think is well arguable) and IF they were for eg 235/75/16 we would be home and hosed in Qld with 265/70/16 for example.

Cheers

they use largest for that vehicle in country of sale - not worldwide

Sorry

[ozscott]

The Regulation (Transport Operations (Road Use
Management—Vehicle Standards and Safety)
Regulation 1999) doesnt actually specify which country - it provides as follows:

"Alternative tyres, rims and wheels
(1) Tyres and rims fitted to a motor vehicle that is a car, car
derivative or off-road passenger vehicle need not comply with
section 7(1) or 8(1) if—
(a) the combination of tyre and rim—
(i) has a diameter that is—
(A) not more than 15mm more than the diameter
specified by the vehicle’s manufacturer; or
(B) not more than 26mm less than the diameter
specified by the vehicle’s manufacturer; and
(ii) accords with the specifications contained in—
(A) if the vehicle was manufactured before 1
January 1974—1 of the following manuals—
• the Tyre and Rim Standards Manual of
the Tyre and Rim Association of
Australia
• the 1981 Tire and Rim Association Inc.
Year Book
• the British Standard, BS AU 50
• the Japan Automobile Tyre
Manufacturers Association
• the Japanese Industrial Standards
(JIS-D4202) and (JIS-D4218)
• the European Tyre and Rim Technical
Organisation Practices (E.T.R.T.O.)
• the Deutsche Industrie Norm (DIN)
7818
• the Deutsche Industrie Norm (DIN)
7817; or
(B) if the vehicle was manufactured on or after 1
January 1974—Table 2 of ADR 23; and
(b) the maximum tyre width is—
(i) for a car or car derivative—not more than 1.3 times
the width of the vehicle manufacturer’s widest
optional tyre; or
(ii) for an off-road passenger vehicle fitted with front
and rear beam axles—not more than 1.5 times the
width of the vehicle manufacturer’s widest
optional tyre; and
(c) the minimum tyre width is 70% of the width of the
widest tyre fitted to the vehicle but not less than the
vehicle manufacturer’s narrowest optional tyre...."

"Specified" and "vehicle" are not defined, but presumably the definition would be "as specified by the manufacturer for that particular vehicle". But no further words could be read into it I reckon...and particularly for a vehicle sold all over the world. The whole point of the section is to exclude application of the ADRs in certain limited circumstances...so the hunt is on for a Disco II specified by LR as being able to use say 235/75/16 in the world...

Cheers

[ozscott]

those faces above in my post should be a "b" but it sees them as a face...:)

[rick130]

I'm not sure, but it was probably whatever was fitted to the Bowler Wildcat which runs D2 axles.

FWIW most use the Michelin/BF Goodrich Rallye Raid tyre in 235/85/16
BFGoodrich Tires - Rallye Raid (http://bfgoodrich.com.au/index.php?a=tires.racing&id=125)

[pohm66]

Not sure where...maybe on the 4wd action forum someone mentioned that they successfully got around the Qld tyre issue by proving that their vehicle had larger tyres in the O/S model. However it might be worthwhile double checking with a Certifier.

I would also check with your insurer to see if they had any quirky rules about this that might void your policy.

[ozscott]

Thats what I am looking at - overseas models most likely, but I dont think that the US ones for eg are standard with large diameter ...mostly lower profile on 18's. As for insurance that a whole other issue...my view is that under the Insurance Contract Act (C'Wlth) the insurer can only reduce its liability by the amount by which the breach of policy (ie having a modified vehicle for eg contrary to the policy wording) contributed to the loss...just make sure you tell your insurer in writing what tyres you have one the vehicle, so that they might find it hard to say that at and underwriting level they wouldnt have insured it in the first place had they known.

Cheers