Thread: Cooper ST's on a Disco 2

I've had cooper STT's on my 2nd set of rims since June and had zero problems with them.

Originally Posted by mrapocalypse

I am currently running 265/70/16 ST on my D2. They don't rub, but give a 7% incorrect speedo reading. The gearing hasn't been noticeably affected.

I have a 2" lift though.

They have been really good, but now I want a bigger STT so mine are for sale. they have about 70% tread.

I'm in Brisbane and they will be pretty cheap!

0418747371

Are not 70 size tyres standard on Discos?? If so there should be no speedo error, that should only occur if you go to say 75s or 80s changing the tyre overall diameter. Something LR should be callibrating for you.
I have noticed since using GPS for speed callibration that most 4x4s have a discrepency straight off the show room floor. I think the standard from memory is + or - 5%.
The only thing that should change with these tyres is the width and this has no effect on speedo callibration.

Originally Posted by CraigE

They do not have a recent history of failing.

They do in this part of the world. Cooper tyres are renowned for extreme chipping in driving conditions that pose no problems for other types of tyres.

sorry Chazb for getting off track

Might be able to throw some light on dealers that don’t want to fit tyres like 245/75 (or larger). Australia has laws on vehicle modifications and these still vary slightly from state to state but are basically very similar. The rules in Queensland (other states maybe vary with different sizes quoted) are very clear - you cannot increase the Total Rolling Diameter by more than 15mm over the largest tyre offered by the manufacturer on your vehicle with your braking spec. There are also points on tyre width, rim offset, rim spacers and others but diameter is what is targeted.
Disco 11 had the choice of 255/55r18 (738mm total RD) or 235/70r16 (735mm total RD). So to keep the vehicle legal the tyre choice can only be (738 +15) 753mm rolling diameter.
245/70r16 = 749 - yes
245/75r16 = 774 - no
265/70r16 = 777 - no
265/75r16 = 804 - no
255/65r16 = 738 – was this the size fitted on 8’ wheels?
This is a legal requirement designed to keep braking to manufacturers spec – the larger diameter tyre the less effective your brakes are – simple. To go over 15mm (in QLD) you are required to get a “Blue Plate” which is the modification inspection and approval process used for all vehicles operational mods including things like larger fuel tanks.

So I think you will find they don’t really know (or care) if it will fit – their book will tell them that it’s not legal, and they might be concerned that if you are involved in a fatal accident on you new taller tyres they will be receiving a visit from the coroner’s investigator to chat (and charge) the guy who fitted said tyre. It’s the Liability thing. And I know that this is happening up here – bloke next door owns a tyre dealer and won’t do it.
I know this is not going to go down well here but these are the facts – increase tyre sizes above the allowed without the Authorities inspection process and you run the risk of the insurance not playing ball, and (we all hope we never are) if you’re involved in a fatal you risk prosecution.

On the Coopers - I bought my td5 2nd hand about 4yrs ago and the previous owner had fitted cooper ST. Vehicle was down right dangerous in the wet, and because most of the driving (with family/kids) is around town the coopers went in the bin.

Originally Posted by CraigE

Are not 70 size tyres standard on Discos?? If so there should be no speedo error, that should only occur if you go to say 75s or 80s changing the tyre overall diameter.


The only thing that should change with these tyres is the width and this has no effect on speedo callibration.

The '70' is actually 70% of the width. A 265 will be a taller tyre than a 245, despite them both being 70 series tyres.

Hey All,

I wasn't expecting such a good response to this thread! Obviously a lot of people have a lot of different opinions on their choice of tyre - and thanks to all of those who have expressed them and given general advice on tyres too.

I think my best bet is to get a few prices for a few different specs (and tyre vendors) and then see what the dealer says they will fit, i.e. what is legal on my Disco 2 according to them. Its gonna mean some homework and shopping around, but is going to be worthwhile if I am going to be safe and not ripped off!

Just for info if anyone is interested I am planning a "big trip" anti clockwise around the country (I have another thread running on prep for this trip) starting in April so will be doing mainly road, some beach and Cape York hopefully. So I need an a/t I figure.

Thanks again to all who have posted.