Ilyam5

Did some major snow driving in 545 during the snowstorm in Boston and NH. 4 days - unplowed roads, 2-3 ft of snow - fun stuff.

The weather here feels like home in Russia now.

But that's what I discovered: compared to 4 years in e-39 M5 through rough winters and 2 years in SMG M3 (all cars run 245/45/18 Snow tires- not perfect for deep snow but we only have it several days a year

545 is very unpredictable - slides are tough to control, rear end is notchy and not stable.
the main reason LSD - the moment one wheel is on ice/snow and another one on the road - all hell breaks loose - all torque goes to the spining wheel - result - you loose the rear end - so driving on the slippery mixed surfaces is the exercise in catching the back end and you do zig-zags constantly (low speed 5-15 mph)
DSC, DTC don't help much, just kill the power and will catch the slide in motion but at a slow speed or stop - you are dead. Small hill with one wheel on ice, one on the road - not going anywhere. Pretty embarrassing at traffic lights with hills. DTC is no picnic either. So I ended up leaving the system off completely and just floating (skiing constantly without LSD)

Today I'm back in M3 - what a difference - the car is planted, stable, rear is rock solid - took it to the same lot and roads to slide - what a beauty - I can place it within inches of the edge of the road - totally predictable / Again same snow tires - reason is M differential lock with 100% power transfer (DSC off).
M5 was similar but with 70% power shift - Boy I miss e39 M5 (it truly is the best car in the world)

Next scare in the snow - active steering. I learned to live with it in the dry but in the snow it's way too twitchy. Slow speed - fishtailing up the snow hill with no LSD trying to catch the rear end constantly giving tiny corrections (correct - pause - return) but the steering is over boosting the corrections so it's very hard to judge. Again in M3 - beautiful, no problems - can have it sideways all day long.

For those questioning driver abilities: 40+ track days a year in M5 and M3. 10 weeks a year of high speed driving in Germany. 10+ years of driving on total ice and snow in Russia in RWD cars.

So what am I doing wrong? It's upsetting to re-learn to drive again? Don't get me wrong, I can adapt to the car and by the second day I was able to master the "skiing" but shouldn?t it be the opposite? Should the car work with you, not against you? Is it too much to ask for 70K USD

So 545 is parked for now, back into M3 for some snow driving. Believe me, I can deal with snow weather in bad cars and take it extra easy. Concern is like with all the cars - if it's so poor in the snow - it will be the same in the wet or dry with much higher speeds. You hit a puddle or oil with one wheel in the summer at 100 mph+ the car will do the same thing to you as at 5mph on the snow

Solution: 1) Beg Dinan for LSD
2) Pop the fuse for Active steering to disconnect it
3) If it snows like that - get the same tires I used in Russia - Nokian Hakkapelita 4 with narrowest possible fitment (bye-bye aggressive cornering in the dry, but unstoppable in the snow)

doctors4bob

did you try dedicated snow tires?

also, you seem to imply this is an Active Steering related issue? (2 in your solutions) . if i had a 545i WITHOUT active steering (no sport package), would I expect different results?

thanks

Ilyam5

did you try dedicated snow tires?

also, you seem to imply this is an Active Steering related issue? (2 in your solutions) . if i had a 545i WITHOUT active steering (no sport package), would I expect different results?
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I do use dedicated snow tires. Just on stock 18" rims. The reason is - better handling on the dry/wet cold highways.(90% of my driving)

You are right 17" narrow fitment 225/50/17 with aggressive snow or studded tire (Nokian, Blizak) will improve snow traction at the expense of dry handling.

You can forego active steering if you don't get the Sport package but you'll miss on the Active Roll stabilization which is a pretty neat feature to have. (not on the race track)
But as of model year 06 you can order 5 series with Sport package and no active steering - which would be my choice.

juan2mini

Ilyam5:
Thanks for the insight on snow driving. I only get into snow while on vacation. I still found your thread most helpful. Many thanks

alex123

Did you try to turn DTC, DTS,etc. off by holding DTC button down for couple off seconds?

Iceman

Press button once, you have DTC only.
Press button a couple seconds, whole DSC is off.

To turn on again, press button once.

Jimbo

Let us know your results once you implement Iceman's info. The driving should be fine with one of the combinations.

realtyman

I understand what Ilyam5 is saying.
I haven't found it to be as bad as he says, but an LSD would make things much better (or at least I could see purple snakes on the hood and the dash melt ).
I've tried it with all systems on, just DTC, and the whole shootin' match off. There is no perfect solution. Luckilly I'm running snows which seems to help quite a bit.
My experience: Still quite capable in the snow, but LSD would make things much better for me and my driving style.

As a side note: I've been in a 3 Loaner for the past week and it is much more predictable with all systems off. Granted the narrower tires could be the difference.
My $0.02.