Thread: D4 standard 19" rims/tyres

Originally Posted by scarry

LR have said that this will change in future models.

Particularly with the Defender replacement,they will keep to "common" tyre and wheel sizes,what ever that means

Read that in the UK's "Car" magazine, LR suggested it will be interchangeable with Toyota!

Just on the earlier comments about vans being too heavy: they get heavy for a reason. Namely the same reason the Disco is heavy - strength.

Plus with a trailer, water, power and refrigeration adds lots of weight.

An example: someone I know bought over a few years a number of Ultimate Off Road branded trailers. They are quite light weight. Their tear is 750kg.

My friend's last Ultimate was weighed at the weighbridge. Its weight was no longer 750kg. Instead, it was a bit over 2,000kg.

Many trailers now have 300kg of water; some have a loo (these days some Parks want a loo and a black water tank for you to go in). So ... that's 380kg alone. Then add solar power weighing 50kg. And awning weighing 70kg. Tent pegs weigh too; A fridge will weigh 60kg plus its contents - 100kg there. Where are we? 600kg already. And no batteries. Or food except for the fridge. Or fuel. Or spare tyres on wheels - which weight 45kg each.

So you are around 1,000kg already. Then add the weight of a trailer to handle the weight, plus its two tyres, and a heavier decent suspension. 2 tonne is easy to get.

And that is why the LC200 is popular - it can pull 3 tonne without worries.

So too the Discovery. But ... can the Discovery's tyres?

They are narrower than an LC200's. And the vehicle weight is quite close. Perhaps that is why the Discovery only has 83 litres of fuel - any more, and their weight might become an issue. Or is it because they want better fuel economy figures, and the bigger the tank, the heavier the fuel economy tests make the vehicle weight.

And if you read the weights of the Disco - its rear axle takes more weight than its front does I believe.

Then add the toe ball weight onto those rear Disco tyres. That weight can be 350kg.

Add another fridge in the back of the Disco too. And a tyre setup. Maybe a long range fuel tank.

Now - put that onto a big 4WD market for Land Rover - the middle east. They have lots of sand.

What do you do in sand? You let the tyres down, to increase the area, by having the tyre go longer (the width gain is much more marginal).

By having an 18" wheel of the same circumference and width at the standard 19" Discovery wheel, you will get a lot more lift or buoyancy from such 18" tyres when deflated to 20 PSI than with a 19" tyre. The equivalent of 900kg less weight on the back, compared to a similarly deflated 19" tyre.

And that has nothing to do with tyre toughness.

So I reckon Land Rover have been very slack with their wheel requirements.

But so too have Toyota with their Prado. Because the Prado VX and Kakadu, cannot take 17" wheels. They are restricted to 18" wheels, due to their KDSS suspension systems. And by the way, the Kakadu does have an air suspension system on its rear live axle. Its not active though the way the Land Rover is.

It seems to me that both companies look at each other. So in the top Prado models, KDSS mean't bigger wheels - so Land Rover said not to worry, we won't bother developing an 18" wheel when we put the big brakes on.

Likewise, Prado Kakadu owners did not like the first 150 series off road mode controls (snow, rock etc like Land Rover), because they were push buttons. So in 2013, the update 150 series Kakadu got a round dial to select the modes.

And Land Rover switched from a round dial for their modes, to push buttons ...

That tells me something about the companies looking at eachother's features.

But really, LR should have made available factory 18" wheels. Very strange that one, because they are a big benefit.