I just got my new snow tires mounted, and what a difference that makes. I can now safely drive this winter. But I do notice that the light rear end with the big power of the XJR spins easily from stop, consistently triggering the traction control. I am thinking of adding a few hundred pounds in the trunk. Any advice?

 

The "Sand bags " from Wal-Mart are great, you can also use the sand for traction if you get stuck.

 

Below is a quote from a Canadian website. I keep a small amount (5kg) of traction sand mixed with road salt in the trunk in case I get stuck. Any more can affect cornering. Adding weight to the cabins interior is the best method so car pooling with your larger friends should keep you out of the snow banks.


Myth # 3: Adding weight over the driving wheels improves traction
In fact: Adding mass, such as sand bags, over the driving wheels of a two-wheel-drive vehicle may effectively improve traction, but only during the initial drive-away phase. In all other circumstances and conditions, the added mass will make the vehicle harder to stop and increase cornering loads, neither of which is desirable. In addition, the position of the mass may aggravate a skid, making it more difficult to correct. In general, it's not a good idea. Once again, look instead at the quality, grip level and proper inflation of your tires. In the cold season, nothing matches the safety and confidence provided by a full set of winter tires.

 

They can call it a myth but it has been tested and it works. I always kept bags of sand, fire wood, or tools in the bed of my 2-whl drive pickup and it did make a difference. As a matter of fact, I drove that pickup on ice and deep snow (not as deep as Canada) when 4x4 where stuck. It all depends on the skill of the driver and his/her knowledge of vehicle operation to road conditions.
I dont drive my VDP on snow or ice, I use my Expedition or my Wife's X-Type.

 

I'm not sure it is that much of a myth ... FWD cars which have engine and transmission over the front wheels (thus maybe as much as a 60/40 F/R weight distribution) perform very well in snow ... the original Mini was legendary in the 1960s Monte Carlo Rallies.

Even so the message really seems to be fit good winter tyres; even 4WD (alone) is no substitute. Both (ie 4wd and winter tyres) is best of course.

 

Even better with studded snow tires which is what I have on my Touareg. I park my XJR for the winter.

Stu

 

The key is the highlighted phrase.

 

Well, the rest is really rather academic ... if you can't actually move-off in the first place.

And obviously once moving whatever methods, if any, one uses to improve traction ... everybody then drives with great care: low speed, no sudden steering movements, start slowing early, and use the box not the brakes etc etc ... don't they (erm ... ) ?

Sure it's no a substitute for winter tyres or chains, but it might just make the difference between remaining stuck and getting going.

[Edit]: Thinking about a bit more over dinner (and 1/2 pt of Wadworths 6X, in the pub) the big drawback to putting extra weight in the boot/trunk is if that places the weight significantly aft of the rear wheels. That will increase the polar moment (moment of inertia about the vertical axis of the car) by more than the extra grip that the extra weight gives you, so once the back starts to slide sideways it will be more difficult to control the slide. And when you think about the overhang of the trunk of an X350 ...

The best place to put the extra weight is probably just forward of the rear axle, ie tucked well back in or under the rear seats, but then you have problems of not damaging the upholstery, and restraining the weight ... a couple of heavy friends in the rear seats - yes; a couple of hundred pounds in the trunk - probably not.

Best thing ... winter tyres; see this video made by '

 

Definitely works in a pickup, as there is about a 65/35 weight distribution, with the drive wheels at the 35% end. Also, you are likely placing the weight over the axle instead of behind it. In a car I would think it would help in a straight line, and on a curve it will help you hit the snow drift tail first.

 

if you want to add weight, ther rear footwells are better. The put more weight on the back wheels, but they also move the weight towards the centre of the car, making it more stable. If the weight is at the tail it will have more inertia to turn a skid into a spin.