Hi guys,

Id like some advice pretty urgently as I had a bit of a brown trowser moment this morning.

I'll explain quickly - we've had our snowfall, and I was calling up to my brother in laws house earlier.

He lives on a steep hill, and there was maybe a 1" dusting of snow. The drive up his tarmacced drive is as I said quite steep, but I drove up it very easily, but felt a bit of spinning at the top of the drive.

When I was coming back down, I knew it was gonna be a bit risky, so used the HDC to come back down which was great until I was nearly at the bottom, when I started sliding for one of his two large pillars.

I had e sense to point the front wheel onto his grass which stopped my, and I proceeded carefully and made it our unscathed.

More embarrassingly, he drove down after me literally 1 minute later in his jeep grand Cherokee with no problems, no skidding and no slipping.

I am running on my 275/40 20 continentals which I hope are the cause of my problem compared to his definite more off road 17" wheels.

I am looking at two options.

1) change to the general grabber AT tyres AJS is selling
2) change to a set of 19s and then some AT tyres.

I know that going through snow should really be no problems for my RRS and that if a 2.5Tonne 4x4 starts sliding in the snow no tyres are going to stop it, but I was very disappointed with the performance of it today.

Looking forward to and advice,

Thanks, MY10 HSE 3.0 TDV6 : Santorini Black : Ebony Interior w/Anigre wood : Privacy Glass (total) : Sunroof : Sidesteps : Hybrid TV : Detachable Tow Kit : Spare Wheel Cover : 22" Dished Supersports

Hmm yet another Conti slagging post?

Well FWIW after more years than I can remember driving "the ultimate driving machines" I spent last winter behind the wheel of a RRS on summer issue Pirelli Scorpions

On the one hand I admit I started the winter as the biggest wuss on 4 wheels after 20y or so with RWD and drove accordingly

Consequently I rarely pushed the car to its limits and all was well
However as I got braver I did see what it would do which was quite a lot actually - and even more on the GGS setting
There is a 500m 10% incline near my gaff which I eventually tried which was easy

In fact I did wonder why people even bothered with winter tyres on LR's

But then for a variety of reasons I decided to fit some Wintracs last months
Ive dropped a size to 19's which covers the cost of a SH set of alloys

And blimey what a machine I have now!!!!!
I live and work around the Peak district
Im not self employed but do need to be mobile in all weathers or else bad things may happen

On Pirellis my RRS was utterly rock steady in snow and ice
I just dont understand the scenario you describe with contis

However on a winter tyre its just completely stunning

Cheers

Thank you very much for replying, I was beginning to wonder was anyone going to answer me!

I'm just disappointed that in what would maybe be about a 1:3 hill my RRS let me down compared to a jeep!

I was just really unimpressed with the response of my RRS ams wondering was blame attributable to poor tyres? MY10 HSE 3.0 TDV6 : Santorini Black : Ebony Interior w/Anigre wood : Privacy Glass (total) : Sunroof : Sidesteps : Hybrid TV : Detachable Tow Kit : Spare Wheel Cover : 22" Dished Supersports

width 275 is very wide indeed. When tyres are wide they act as ski, literally. This size is not the best choice for winter.

If I were I would get different tyres. I just bought Vedestrein 255/50/20. James just posted a list of LR approved tyres. Vadim A.

Hi Vadim...
I agree 275 is probably too wide for snow...however looking at your choice I think you should have gone for 45's rather than 50's otherwise your speedo will be reading almost 5% slower than your actual speed..not a huge problem if your are pottering about at 30mph but could be significant once you get to higher speeds!!!

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

HDC is fantastic in a low-friction situation, but any ABS based system in a zero-friction situation will get confused as it is unable to tell the speed of each wheel.

If you were in compacted tracks then the chances are that you found a section with zero-traction. In this instance you need to add a low speed (low box / 1st in command-shift) in addition to HDC.

On ice you are better off without ABS and to cadence-brake, hence perhaps what you experienced. In summary, HDC is mindblowingly brilliant, but you do need one wheel that can achieve at least partial traction on your descent.

Also check your HDC target speed is set to the slowest setting via your cruise switches.

James

PS I'd never hear the last of it if it had been my brother-in-law!!

Thanks very much for the advice.

I really believe the HDC is a great system, but was just very annoyed and somewhat embarrassed that my RRS which I would have assumed is a better 4x4 than a jeep grand Cherokee didn't perform nearly as well.

I understand that my 275 section 20 inch wheels on what are essentially road tyres will not perform as well as 17inch more narrow all terrain tyres, but if I changed to 20" all terrain tyres or even 19" all terrain tyres will I still be let down in similar sutuations

I am going on an off road experience day o. Tuesday so hopefully I will pick up some fresh ideas, as I really hope my RRS will outperform any rivals this winter! MY10 HSE 3.0 TDV6 : Santorini Black : Ebony Interior w/Anigre wood : Privacy Glass (total) : Sunroof : Sidesteps : Hybrid TV : Detachable Tow Kit : Spare Wheel Cover : 22" Dished Supersports

Hey wackyjim,

I was not aware of this problem... Thanks for your info. However, I already paid for the tyres so I think I will fit them anyway and keep what you suggested in mind  Vadim A.

You can use the electronic trickery in the RRS as James suggests to improve your grip in marginal conditions.

However at the end of the day, no matter what the terrain, you are limited by the friction generated by the tyre contact patch. The grip afforded is a combination of the vehicle weight, contact patch size, tyre compound, tread pattern and depth to name but a few. What the RRS does is try and keep you from exceeding the friction available from the tyres. This can also be done the old fashioned way with use of the gearbox, steering wheel, accelerator, and brakes though it takes some practice. As James suggests you can help the RRS by selecting low box command shift first and dropping the HDC speed to try an limit any sudden changes of momentum that will overcome the grip.

The RRS is a mightily clever piece of kit that draws on LR's years of experience but at the end of the day you are limited by the tyres and the ground under them. You could go for an AT tyre or a winter tyre to improve things or just get some snow chains. Go for a narrower tyre though as 275 is a bit wide for snow. My only other bit of advice would be to brake test the surface at the top of any decline to gauge the levels of grip. It will give you an idea of what speed you can safely travel.

My drive is a 1:5 which is cobbled in part and I haven't had any issues on 255/50-19 Pirelli Scorpion assimetrico using low first with no HDC (I don't like HDC I do it the old fashioned way!) despite it being snowed up and partially covered in ice.