Here's one for you all, was poking around in the engine bay of my RRS yesterday and noticed how bloody massive the viscous coupled radiator fan is, big enough to convert the RRS into a hovercraft!
A few years ago, I removed the same from my Mitsubishi Pajero (3.5 V6 petrol) and replaced with a Kenlowe unit. Not only did the engine become noticeably quieter, the overall fuel consumption went down from 22mpg to 24mpg.
Range Rovers and big 4x4's are designed for use in hot weather, mud plugging, climbing sand dunes, towing big trailers etc, so no real need for a huge energy sucking fan to be running the whole time, especially for normal road use. The only time I needed to run the Kenlowe in the Pajero was when stuck in traffic...
Anyone thought about binning the viscous unit, or at least temporarily removing it?

From Disco 3 forum
http://www.disco3.co.uk/forum/topic53201.h...ectric+fan Currently MY16 Disco 4

Ex RRS MY13
Ex Discovery 3 MY08

I think it unlikely they chose mechanical for fun.

It's actually a cleaver electricity controlled fan increasing speed when air con on etc.

Apparently full fat owners have removed them. Not sure what engine that was though.

Thanks guys, sounds like some more investigation is called for... certainly looks and feels like a basic viscous unit to me
Don't know why they didn't use an electro-magnetic clutch as on an AC pump.

It is a variable speed system.

To get perfect cooling v fuel consumption ratio.


I guess the vicious is also fail safe.

When at speed the fan is turned by ram air alone so there is no load on the engine.  Visiting from DISCO3.CO.UK
2006 Discovery 3 TDV6 Auto HSE Zambezi Silver

Ram air!!! I doubt that, have you seen the amount of stuff the air has to pass through?

You can observe the effect in the duty cycle and speed live values. The air has to flow nicely through the radiator else it'd be utterly pointless.  Visiting from DISCO3.CO.UK
2006 Discovery 3 TDV6 Auto HSE Zambezi Silver