Best Practices for Open Diff Driving in the Snow

[M0nk3y]

To who drives in deep snow, I need some suggestions.

I currently run Blizzak LM-25 tires on the 128, not the best...but I got them used with a season on it to get me through this summer until I get Ice-X tires next year.

Anyways, I'm experience so far, the car doesn't like deep snow at all. Instantly, the car will lose grip in a wheel and go open diff. The DSC tries it best to try and correct, but ends up cutting engine power.

Usually, I'll press the DSC button once to get rid of the e-diff and go full open diff and just hope my best I can spin the tire to get grip.

For example, today I came home to around 7" or so in my driveway, and with a small incline I got the car stuck. I've had no problem with an E92 xDrive with Ice-X tires.

However, this obviously isn't the best solution to try and always turn off traction and hope for the best.


Have anyone tried pulling the e-brake slightly to lock the differential and try and get both wheels to spin with the DSC pressed once?

Ultimately, I'm trying to figure out a way to cope with an open diff. I'm no stranger to driving in snow. I've done with with a FWD car, AWD car, but this is my first RWD car in the snow

And tips/suggestions appreciated.

[Vas]

I would be interested in hearing some advice as well.

The zhp is also my first car with an open diff which i despise. Every other car I owner had an lsd.

[Newjack]

Also interested. The BMW is the first rear wheel drive car and first with an open diff. Winters here have been mild so I haven't really experienced many "snowy" driving conditions.

Sent from my Nexus 4 using Tapatalk

[alexandre]

We get a lot of snow up here (3 ft to date) and honestly my strategy is just to predict and disable DSC in advance. My tires (WS-60) get good reviews for deep snow and I still spin a ton, but haven't ever been stuck. The engine has too much torque lol.

Where feasible go up hills in reverse as the car will be "fwd" and have more grip in fresh snow... But otherwise it's just a matter of predicting the terrain where you're gonna need more spin than stability and being very gentle on the throttle.


iP4S + TT2

[ZHPRegistry.net]

The best practice for the E46s is to disable the 1st stage DSC, leaving the "poor mans LSD" feature on. This assumes that you understand what you're doing with the right foot and know to back off well in advance before you find yourself facing the road in the wrong direction. The DSC kicks in way to early taking away all the possible momentum that you often need to overcome slippery surface uphill.

[3ZHP]

I grew up in Buffalo, NY and learned how to drive in the mid 70's. That was before front wheel drive and (Positraction) or LSD was a special order option so, most cars didn't have it.

The trick we learned in deep snow was to feather the gas and hope the rear end didn't break loose. If it did, you needed to (rock it) meaning roll up the rut in drive, then do the same in reverse and just keep increasing the rock in till you can get it unstuck. A lot of gear slamming went on in those days.

The other option for deep snow, was Tire Chains. They work great on snow covered roads but, your limited on speed and the have to be removed once the pavement is visible. If you don't you will prematurely wear out the chain that can break and destroy your fender from the broken chain hitting it. FYI: plastic chains are also available and may not work as well but, are less destructive if they break.

[mimalmo]

I always had the best luck when doing the single DSC button press. It allowed a bit of oversteer but didn't cut the throttle. DSC would only step in if you got way out of shape.

[BRGcoopahS]

I'm finding that having the first stage of DSC off is the best. I just went out for a drive in the snow ( apparently north jersey is in a state of emergency lolol) and did ok with it off.

I'm driving on conti DWS. So these aren't even winter tires. The car was sliding a bit down slight hills and I definitely had to be careful, but overall for all seasons I'm impressed. I enjoy the challenge, call me crazy. I'd rather learn to control the car with DSC off than "play it safe" with some fwd car and traction control on.

Turning off stage two in a parking lot was mega fun :D

[BavarianZHP]

Anyone use snow socks? As for driving: slow and maintain tons of distance from cars in front of you - especially on downhills.

[stephenkirsh]

The best practice for the E46s is to disable the 1st stage DSC, leaving the "poor mans LSD" feature on.

Ok newbie question: What's "1st stage DSC" on an E46? I thought it was simply just ON or OFF.

[Avetiso]

Ok newbie question: What's "1st stage DSC" on an E46? I thought it was simply just ON or OFF.
Press once to turn off traction control. Hold to remove stability control.

Something like that.

[BRGcoopahS]

When you hold the DSC button there will be a "brake" light lit up to let you know all aids are off.

[az3579]

This may be painful for you to do, but to get start moving, you have to slip that clutch with very minute throttle adjustments. If you slip it just right, the car will start to move forward enough to get a grip and continue the momentum. If it is literally stuck, then you'll have to employ the "stuck" methods to get out.

Whenever I have to get onto an incline, I start off with some speed. You must keep momentum up in order to be able to get through deeper snow. I refuse to stop on hills for this reason. Once you stop, the only way to go is down if the snow is deep enough.

[BavarianZHP]

Agreed, hills are the worst. Avoid them at all costs if you can during slippery season.

[Hornung418]

Put my skills to use today. Had six inches of unplowed snow on the roads when I woke up.

Street is level in the middle and sloped on either side. I chose to go down the hill. It took me ten minutes of rocking and spinning to get out of my spot. Traction control off.

The ride in was even sketchier. Lots of back roads that were plowed but the wind was blowing snow from the open fields back onto the pavement. Little skittish in some areas but overall proper tires and some common sense proved victorious.

Drive safe!

Sent from my GS3.

[ELCID86]

Played with this today. Stage 2 in a snow covered icy lot was a ton of fun!

[ZHPRegistry.net]

Ok newbie question: What's "1st stage DSC" on an E46? I thought it was simply just ON or OFF.

I know other members commented on this but I will expand in case it adds useful info. Pressing and releasing the DSC button shows the yellow triangle sign on the dash. This means that the car will not attempt to cut down on the throttle input not will it apply individual brakes to correct the yaw angle of the car. However the rear brakes will interfere when the difference in rear wheels reaches a specific threshold. It will slightly apply braking power to the wheel that is spinning faster which in effect will cause the open differential to send more torque to the other side. You want this feature in snow because you often find yourself not moving ahead because one side of the car has lost complete traction. In a Limited Slip setup this feature is essentially pointless because there are mechanical means by which the rear wheels always want to travel at the same speed. The problem with this "poor mans LSD" is that it is often abrupt so in a race situation is does more harm than good, it also has a major flaw in that the friction generated by the brakes on the faster wheel does not translate into spinning motion on the other wheel (unlike a real LSD). So in short, it is useful in snow but lacks the smoothness you need in high performance driving.

If you press and hold the DSC button for 5 or so seconds you will see the yellow BRAKE light in addition to the triangle. This basically disables everything. If one of your rear wheels is sitting on bare ice and the other one has some traction you will not likely move even an inch.

I absolutely love what they've done with the rear end on the brand new M3 (F30). While the M locking diff on the E46 M3 is a nice improvement over the old school ramp based LSD the newest unit can electronically change the locking ration fro 0 to 100. I would LOVE to try out the new M3 with some nice set of Hakkapeliitta R2s in snow...

[az3579]

^ isn't a 0-100% locking range effectively the ultimate LSD?
I can't wait to drive the new F80/F82 M3/M4 (whichever is fine by me :biggrin). I see one of those in my future, it'll just take a long time until they get used enough where prices aren't astronomical. :(

[BRGcoopahS]

Put my skills to use today. Had six inches of unplowed snow on the roads when I woke up.

Street is level in the middle and sloped on either side. I chose to go down the hill. It took me ten minutes of rocking and spinning to get out of my spot. Traction control off.

The ride in was even sketchier. Lots of back roads that were plowed but the wind was blowing snow from the open fields back onto the pavement. Little skittish in some areas but overall proper tires and some common sense proved victorious.

Drive safe!

Sent from my GS3.

What tires do you have?

[Hornung418]

What tires do you have?
Khumo Extsa 4S.

[Rovert]

When I have heavy snow on incline with heavy snow I will make sure I turn off the first stage of DSC (ASC off) so I can at least spin my one wheel. LOL. Spinning mildly allows me to keep forward direction up the hill. If you spin too fast you'll end up losing more and more traction as the snow stuck in the tire sipes don't have time to grip the surface snow for forward movement. Slow enough spin grips just a tad and kicks the vehicle mass forward. You'll need to counter steer slowly as you do this so that DSC doesn't take over a full sideways drift and brake your spinning tires.

I can look silly but as Alex said, driving backwards makes the car FWD and it goes up hills without much spinning. I've tested this on a curved uphill. I only made it up half way driving in RWD forward mode. I turned the car and drove up backwards and made it up all the way with some mild tire spinning. I've also used this method on inclined parking lots so I always pull in if I know I may need to drive backwards out of there. I've used this method with Blizzak and Dunlop winter performance tires. Driving on more aggressive winter rubber will yield much better snow traction than a harder compound performance winter.

[terraphantm]

... once to get rid of the e-diff and go full open diff and just hope my best I can spin the tire to get grip.

If the 128's ediff is the same as the 135's, it doesn't enable until DSC is completely off.

Also, your M would probably do a lot better in the snow. I know mine was much easier to drive than the ZHP (except you have to be more careful with the throttle)

[M0nk3y]

The M isn't seeing salt, and would probably act like a really good plow ;)

Anyways, I should update this thread (duh!).

I took my dad's E92 Michelin Ice-Xi2 tires and threw them on my car, besides them sticking out 12mm more, I took them for a spin around the block on packed snow, and some powder.

All I can say is, the car is completely different animal. Even with 225s in the rear (versus 205) the car griped SOOOOO much better on hills. I purpose parked the car on hills to take off and with minimal tire slipping the car just took off. Pretty crazy what tires can do.

Confirming this, is that my tires just absolutely sucked today.

-10F outside, and the tires just turned to rocks. Couldn't grip on any pavement with minimal coating of anything. Just not impressed with the "performance tire".

Ordering Michelin Ice-Xi3s tomorrow and will be mounted soon. Can't go longer without them this early in the season

[az3579]

The M isn't seeing salt, and would probably act like a really good plow ;)

Anyways, I should update this thread (duh!).

I took my dad's E92 Michelin Ice-Xi2 tires and threw them on my car, besides them sticking out 12mm more, I took them for a spin around the block on packed snow, and some powder.

All I can say is, the car is completely different animal. Even with 225s in the rear (versus 205) the car griped SOOOOO much better on hills. I purpose parked the car on hills to take off and with minimal tire slipping the car just took off. Pretty crazy what tires can do.

Confirming this, is that my tires just absolutely sucked today.

-10F outside, and the tires just turned to rocks. Couldn't grip on any pavement with minimal coating of anything. Just not impressed with the "performance tire".

Ordering Michelin Ice-Xi3s tomorrow and will be mounted soon. Can't go longer without them this early in the season

And this, folks, is why all seasons are inferior in snow and extreme cold.
Thanks for the info, Kyle.

[M0nk3y]

And this, folks, is why all seasons are inferior in snow and extreme cold.
Thanks for the info, Kyle.

These are performance SNOW tires.

Blizzak LM-25s. Google them. You would think with a name Blizzak on them, they could tolerate these temps and snow conditions

Sent from my XT907 using Tapatalk

[danewilson77]

And this, folks, is why all seasons are inferior in snow and extreme cold.
Thanks for the info, Kyle.

Inferior to what?

Sent from my SCH-I545 using Tapatalk

[terraphantm]

LM-25s are awful. I'll admit the M3 was absolutely a nightmare to drive with them. Dunlop Wintersports were much better. Michelin PA4s are supposed to be even better. And a non-performance tire like those X-ice's will probably do great


Inferior to what?

Sent from my SCH-I545 using Tapatalk
To winter tires. And to summer tires in the other 3 seasons. Just terrible tires that never should've existed.

[danewilson77]

Disagree. I love the tread wear an A/S tire has to offer. I been happy with them (DWS) in the snow/ice as well.

I understand your point though.

Sent from my SCH-I545 using Tapatalk

[az3579]

These are performance SNOW tires.

Blizzak LM-25s. Google them. You would think with a name Blizzak on them, they could tolerate these temps and snow conditions

Sent from my XT907 using Tapatalk

My bad. Thought you had all seasons and forgot you were running LM25's.
*Quality winters are still the way to go though. :thumbsup

To Dane:
I mainly posted that because I had a couple of friends that were like "all seasons are fine in the winter" and I've been trying to give them examples of how they have to get good quality winter tires for the winters we get over here. I linked them to this page right after I posted that. Even with my mistake, they can see how the all seasons wouldn't cut it anyway if even a winter rated tire couldn't stand up to these conditions compared to the best you can get.

My next experiment to turn them into believers is showing them how my RWD BMW with proper winter tires can get up a snow covered hill with no drama. Can't wait to see their reactions.

[terraphantm]

My bad. Thought you had all seasons and forgot you were running LM25's.
*Quality winters are still the way to go though. :thumbsup

To Dane:
I mainly posted that because I had a couple of friends that were like "all seasons are fine in the winter" and I've been trying to give them examples of how they have to get good quality winter tires for the winters we get over here. I linked them to this page right after I posted that. Even with my mistake, they can see how the all seasons wouldn't cut it anyway if even a winter rated tire couldn't stand up to these conditions compared to the best you can get.

My next experiment to turn them into believers is showing them how my RWD BMW with proper winter tires can get up a snow covered hill with no drama. Can't wait to see their reactions.
This is my biggest problem with all-seasons, no one buys proper winter tires nowadays. To the point where people tell me I'm wasting my money by buying winter tires instead of all seasons. End result is there are loads of accidents every winter which could have been prevented. Some of these folks might rear end us, and in most cases, our commutes take longer thanks to those tires.

I finally got my dad to switch this year (Super Sports in summer, Wintersport 4Ds in winter) and he can't stop raving about how much better the car is

[BRGcoopahS]

Disagree. I love the tread wear an A/S tire has to offer. I been happy with them (DWS) in the snow/ice as well.

I understand your point though.

Sent from my SCH-I545 using Tapatalk

I agree. The DWS are perfectly fine in the snow.

[M0nk3y]

I should tape a video of me trying to get up my street tomorrow. It is really comical

Sent from my XT907 using Tapatalk

[BRGcoopahS]

How bad is the snow and your performance blizzaks? I just can't see how bad they can be. I've been driving with DSC off in some pretty decent snow storms, up small hills with no problem. Sure my Conti DWS will slip under acceleration and slide under braking, but nothing terrible. Yesterday the roads were pretty icy and even with DSC off and accelerating harder than I should I kept it cool.

[M0nk3y]

How bad is the snow and your performance blizzaks? I just can't see how bad they can be. I've been driving with DSC off in some pretty decent snow storms, up small hills with no problem. Sure my DWS will slip and slide under braking, but nothing terrible. Yesterday the roads were pretty icy and even with DSC off and accelerating harder than I should I kept it cool.

Well, I got stuck in the driveway with snow up to my bumper.

Today was a sheet of ice on the street topped off with 3 inches of snow. I refused to stop at our stop sign halfway up the street because I would of never made it up the hill. I essentially go up our street sideways until I can manage to level out and get into 3rd gear.

Like I said, the Michelins I didn't have this problem, so I think it is safe to say the LM-25s are glorified crappy all-seasons

Sent from my XT907 using Tapatalk

[BRGcoopahS]

Well that's more than I've been through. Although I've purposely drove into mounds of snow that were nearly up to my bumper and haven't gotten stuck from a dead stop. To tell you the truth, I want more snow. I am loving it.

I have driven my friends '13 SLK on standard blizzaks and i will admit there is a difference, a huge one. He later gave me a test drive in them and I was amazed to say the least.

[Rovert]

You need to be in Vancouver where temperatures hover around snow melt. That creates super heavy snow and anything that is more than a few inches above front splitter level will get the car stuck with performance winters. I've had Blizzak LM22, Blizzak LM25, and Dunlop 3D. When the snow is light and temps stay well below freezing, the performance winters will go through a foot of light powder. But as the snow starts to melt and creates thick heavy slush....it's game over for more performance winters as they don't have heavy aggressive enough siping to grab the heavy snow to create effective forward movement.

[terraphantm]

I agree. The DWS are perfectly fine in the snow.

Maybe if you don't have hills. I didn't like them even in AWD cars

And I agree with rovert, slush is a big problem with performance winter tires (though I haven't gotten a chance to test the 4Ds there). They also generally become useless once they're half worn

[Rovert]

Every tire that hasn't slipped off the road is perfectly fine in the snow. LOL. It's when the tire leaves where it should be is when the owner of those tires thinks, "What if winters...." Being able to take evasive action to avoid an out of control car at 20MPH versus a slightly less aggressive tire that would only be able to do it when at 15MPH could mean the difference of contact or no contact. I can say my performance winters are enough until they aren't and I lose control compared to X-ice tires....human nature. :)

[M0nk3y]

$700 later, I'll have Michelin Ice-Xi3 sitting outside the garage. Gotta wait for TPMS to arrive (I'm currently running the wrong freq) before I can mount. Thankfully it should be warmer within a couple days that I don't have to depend on these tires

Sent from my XT907 using Tapatalk

[az3579]

Maybe if you don't have hills. I didn't like them even in AWD cars


This, in regards to the DWS. Performance with the DWS tires in snow on my car have been mediocre at best, in the past. Glad it's working out for you though, DW(S) [see what I did there? :biggrin]. :thumbsup


Every tire that hasn't slipped off the road is perfectly fine in the snow. LOL.

Except for the ones that do slip ON the road and into someone else's car. :rofl

[cakM3]

Interesting read Kyle. This winter season I went with Blizzaks LM-60's and put in a 3.46 LSD to ready my ZHP. After the recent big snow storm were we had (at least 6" of snow), I am very pleased with my current "winter" setup. I purposefully drove on the back roads as I knew they would still be full of soft white stuff....I was not disappointed!

At points on my travel route, the Arqray lip dug up the snow and put it straight up in the air where the ZHP ran right through it....the LSD did it's job keeping power firmly planted on my rear wheels thanks to my new LSD and along with my DSC the ZHP performed flawlessly. Going around the twisties, I felt very confident running my LM-60's and look forward to more snow during the upcoming months...

All I can say is that my ZHP in it's current setup is awesome to drive in the snow! No complaints with the LM-60's either ;)

[Rovert]

Charlie let us know on Friday how back streets are with LM60's. It seems Friday is when the light, fluffy, grippy snow will turn into heavy slush which could present some challenges to performance winters. I want to know how they are because my next tires might me LM60's as Vancouver hardly gets snow (50F today) and I drive aggressively. I'm running on 3 or 4 season old Dunlop 3D's right now so I know my place if it snows 6".....stay home/work from home! LOL X-ice 3's would probably melt in one season the way I drive...LOL.

[cakM3]

Charlie let us know on Friday how back streets are with LM60's. It seems Friday is when the light, fluffy, grippy snow will turn into heavy slush which could present some challenges to performance winters. I want to know how they are because my next tires might me LM60's as Vancouver hardly gets snow (50F today) and I drive aggressively. I'm running on 3 or 4 season old Dunlop 3D's right now so I know my place if it snows 6".....stay home/work from home! LOL X-ice 3's would probably melt in one season the way I drive...LOL.

No problem Trevor! :thumbsup Now with my current "winter" setup I look forward to snows...:biggrin I only drive the back roads because the LM-60's have so much grip I feel very confident that my ZHP won't get into any trouble...I know with 6" of snow on the back streets and the road hardly plowed, these tires carved right through the streets without any difficulty. I even tried to slide the car but with my LSD I could throttle the gas and let her rip! It was a lot of fun to drive....that's for sure! I had a big grin the whole way back until I parked my bimmer :thumbsup

I will post my thoughts based on Friday's driving Trevor if we get snowy slushy weather :thumbsup