Leslielp

I drove my C-Class in snow lastnight and with my AMG 17" All season performance tires was able to maneuver, start off, and stop better than in my GLK 4Matic with snow tires?

I was taking off leaving in the snowdust everything from Subaru to Lexus and non 4 wheel drive cars. Its the best snow driving experience I have ever had. So much control and the breaking was well as good as dry pavement. Not once did my ABS come on and I think on one sharp right hand powered turn did the traction control come on.

I have to assume that the new 4Matic driven in E-mode in the C-Class is doing something totally different than my GLK 4Matic.

Lower suspension and a brand new set of tires can account for some of this I am sure but does not seem to be the whole story.

I worry about becoming too confident in this first snow performance and will still be looking at some snows but I am in no rush now, maybe next winter

jctevere

I don't think that 4matic has been improved on 2012 models vs 2008-2011 c-class models. I do know though, that it was improved for the introduction on the w204 and GLK.

Something to note though, is that the 2012 models have a new 7G tronic PLUS transmission (resulting in the blue efficiency badging), so maybe this newer revised transmission is the result of the better snow performance?

Most likely: Although people say "snow" the conditions can widely vary. Packed snow, icy snow, and fresh snow are completely different animals.

acr2001

4Matic is great, I love it, and the last major redesign of the 4matic system on the c was when the w204 came out. Having said that, I'm sorry to tell you but I think a lot of this is in your head. 4x4 systems have nothing to do with stopping power in snow and there is no way all seasons beat snow tires on the other 4matic vehicle even if it is an older version. What you've posted appears to violate the laws of physics!

As for control and acceleration in snow, it is HUGELY improved in my 2012 C300 too, but I came from a 4matic W203, so a much older system.

2012c350

Could be that other drivers figured there's no reason to push it off of the line with snow covered roads.
Although traction control has good qualities, I've never been partial to it. Tires slipping is natures way of saying that you're trying to drive too fast for conditions...

That being said, I don't know if there's any improvement with the latest MB AWD.

alanedinger

Hi,

The handling and acceleration is likely attributed to the lower point of center in a C-Class. The GLK rides higher and gives you more sway. This contributes to a different perception of handling too.

However as for stopping, the only advantage that you have is 4-stop-o-matic, meaning 4 wheel disk brakes. A 4-wheel drive gives you absolutely no advantage over stopping physics. But 4-brakes are better than two (what doesn't have 4-brakes these days except a motorcycle) and the lower point of center will make stopping feel better.

My dealer's runners all say that they do not like the way the GLK handles in the snow. However they drive all models, so they are going to prefer MLs over GLKs, etc.


I think this is a safe worry to have--at least as far as stopping is concerned.

If you want real snow/ice performance you may want to consider a set of ice tires.

-Alan

kevink2

How much are the snows worn vs the A/S wear ??

This general statement is not really consistent with applied physics. 4WD predates anti-lock brakes. There are still 4WD vehicles on the road with no ABS, and limited or locking differentials. As they do for traction, they also tend to prevent one wheel from locking/skidding ... some better than others.

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Leslielp

I should note that I am not new to winter driving. Have been driving on snow for some time in manual trany to AWD auto to 4Matic so I dont think its my imagination. Experience gives you the ability to predict and react to loss of traction that only snow can produce.

I normally drive below the speed limit when there is snow on the ground, even more so in heavy blowing snow.

My Bridgestone Ice have very little wear and are mounted on steel rims. (just 2 snow seasons).

My ride is new but it defies my expectations. All season performance tires with little wheel well clearance on what feels like hard rubber tires. Cleaning the snow off the car I was expecting the drive home to be cautious and slow. I did not think much at first because i was driving for the conditions but after seeing others struggle to take off smoothly I realised it was the car. It was only after did I start pushing the car even venturing into the right lane.

With the snow now gone it will be a few days before I have to venture out in snow again.

alanedinger

Hi Kevin,

I didn't bring ABS into to the conversation on purpose because of the highly precise and proprietary algorithms that come into play.

Continuing, If you apply brakes on a surface that is providing severely limited traction, a 4-Matic effectively plays no useful roll in stopping distance as far as the engineering of the 4-Matic goes. However, since the 4-Matic adds more weight to this moving system, there is more inertia to stop, and one could suppose that a 4-Matic would actually require a longer stopping distance. One could also suppose that the added weight may cause a bit more digging into the surface thereby aiding in stopping somewhat, but the surface would have to be the right kind of softness to allow this.

Since you mentioned applied physics, were you referring strictly to practical results or more toward the engineering side? Since I drive both vehicle types regularly, I can attest to the fact that the result is no net difference under the same conditions.

One last thing, since the 4-Matic does tend to add to level of confidence in driving in snow/ice it does tend to bring a hazard with it in being over-confident when you need to stop. -At least for me.

If you have some specific engineering data to indicate a controlled test I'd love to see that. As for learning, I would really like to see a controlled conditions test between the exact same RWD & 4-Matic, or Non & X-Drive under snow/ice conditions regarding stopping as would normally occur in city traffic conditions.

-Alan

acr2001

If I may further complicate the thread (I'm so good at that!) I'd like to mention that under heavy snow ABS often INCREASES your stopping distance (but it gives you better control) this is because ABS prevents snow piling in front of the wheels - something that can actually help you slow down.

2012c350

I've had people argue that with me for years...despite the fact that I've proven it to myself in parking lots by letting ABS stop me vs pumping the brake.

Vai

Before I purchased a 2011 C300 4Matic I drove an Infiniti QX4 (SUV) and I think that the 4Matic is significantly better in the snow.

This could just be my personal opinion and not scientifically proven but I feel like there is much more control in a sedan over an SUV in the snow. I remember with the truck I was much more worried about it flipping if I slid out of control. Perhaps this is what kept me from pushing it really hard (not that I really would with any car in the snow). The low center of gravity makes a huge different when handling especially in slippery conditions.

Let me ask you one question though. How are the defrosters in your car? Mine are very weak and there are two C-Classes in the family (2011 and 2012) and both are very weak. This causes ice and snow to build up during the drive and I can't see a thing. I think even the windshield wipers are weak as they leave many streaks on the windshield even with washer fluid. What are your thought?

acr2001

Pumping the brake would defeat the purpose - snow would still not pile in front of the wheels. In order to test this somewhat scientifically you'd have to try it once with ABS on, and again with ABS off and stand on the pedal, no pumping.

Leslielp

i am not sure if the defrost system is weak. I did notice that both front windows and the extreme sides of the windshield were getting foggy. I had the side vents pointed away from the windows and the AC was not on. After pushing the Auto and pointing the side vents the windows cleared up after about 2 min. I think it would have been faster if I had pressed the MAX Air.
I did drive off with windows slightly foggy so it cleared up as I drove. The rear and side mirror defrost seems to work as well as on my GLK.

LaicepsYdobon

In my opinion the defrosters are fine, never really had a problem with them. As for the wipers leaving streaks; try wiping them with a wet paper towel to remove any debris stuck to them. Or even better have your dealer replace them. As a rule I have my dealer replace mine on all our cars in the fall before the winter mess comes. Also check what kind of washer fluid your car is filled with. At proper dealerships they have a summer mix (dissolves protein better; ie: dead bugs) and a winter mix (lower freezing point with chemicals to prevent salt buildup) as opposed to a general "all-season" mix. See if they have a proper winter mix formula. If they don't you can get it yourself and it should significantly help out in the winter.

http://www.prestone.com/products/car...s/product_list

2012c350

In theory. That's the whole point behind ABS is that it does the pumping much more quickly/efficiently. I'm not saying that snow piling is the difference, just that my ABS does not give me shorter stopping distances for whatever the reason. Maybe my F150 has a bad ABS system...All I know is that I almost always beat ABS by pumping manually in icey/slushy snow. I've tested it many times, back to back exactly as you described.

ETA: If by "off", you mean disabling it, no I haven't manually disabled it for my testing.

kevink2

Hi Allen,

I was considering a limited, specific situation with patch-like iced spots, and a steep downhill turn into a steep downhill driveway (typical for me). If in an old Bronco with an oem detroit locker, if a rear tire hit the ice during downhill turn-in, the locker would prevent that wheel from locking up, and providing better control with the rotating wheel vs a locked one, going in and out of ice patches. I'd have to research all the old 4WD systems for other examples.

As far as tested stopping distances, abs prevents wheel lock and generally improves stopping distances. Some old 4WD's also prevent lock-up, as I described, and should provide slightly better stopping distances.

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acr2001

Yes, so it sounds like you agree with me then. I was stating that ABS increases stopping distance in snow (under certain conditions). As far as pumping the brakes in snow, plus doing it with ABS on, that combination should certainly increase your stopping distance! Maybe you perceive a shorter distance when you pump the brakes because you feel less "sliding" but it isn't likely to be the case.

kevink2

I see no reason to doubt you. Your 2001 ABS may have been improved on the new F150's.

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