Jerry MB230K

Driving 55 mph on a 55 MPH road, and my MB slides about 1 or 2 feet to the left when i'm trying to drive straight. Didn't notice any flashing triangles on the dash to indicate any ASR or other systems engaged.
I'm quite surprised that a new car with new tires and advanced stability control would swerve to the left.

Jerry MB230K

Forgot to mention .. it was raining heavy when my car hydroplaned.

MarkL

When tires are hydroplaning, there is insufficient contact between the tire and the road to hold the vehicle in place. Since all anti-skid systems use braking and/or engine output reduction to control the unwanted direction, it also depends on tire traction on the road to correct the problem, right? I mean if you drove over a solid section of ball bearings, no anti-skid system would help. You need sufficient traction at one or more corners to stop the skid.

avlis

You say it slid to the left. Did it "turn" or "steer" to the left or make a lateral "shift" to the left as if all 4 tires moved sideways?

I think the ESP system compares driver input to "yaw" sensors and makes a determination. If the entire car moved laterally, I think the yaw sensor would be unaffected and still think the car was on a straight course, hence, no flashing triangle. If the rearend started to "come around" the yaw sensor would see that and attempt to straighten things out.

NANA

Just out of curiosity, what kind of tires do you have? Do you also have C7 package?

galaxygrrl

Not that this would help much, but did you have traction control on "W". It does make a difference. Hydroplaning happens, there is not much you can do about it, but stay calm and act smart.

WebGuyNJ

The 'W' setting is only available on automatics, correct?

Lynn

The "W" setting is not part of the traction control. The "W" setting forces the automatic tranmission to start in second gear.

MarkL

That's right, and it also uses a 2nd reverse gear. I don't know where galaxygrrl got that info from!

mverboom

I did a driver training course with some friends. Two of them also have a c270cdi, 1 is almost the same (also a manual). His was not very stable when braking and doing evasive manouvres on a wet and slippery underground. Best to describe it was that is was nervous. Mine wasn't. The instructor thought it was the width of the tires, but that wasn't it (mine are wider). It turned out that I have Pirelli's and he has Continentals.

Come to speak of continentals, everybody in my group who had stability problems had continental tires...

Mark

Jerry MB230K

All systems were on .. the car was not in "W" mode .. not sure if 'W' would make a difference at 55 mph when the auto xmission is already in 5th gear.
I have standard tires ( not c7 )

galaxygrrl

Sales guy who said to always use it when it was wet and that it would help.

awaken

Common misunderstanding. It helps only start, not to drive on slippery surfaces. If you start on 2nd gear instead 1st less torque applied to the wheels and less chances to wheelspin. The same technique applicable for manual tranny

DtS

The "W"-mode also engages another shift-program so that upshifts will be done sooner (given that you don't floor it, then it will be no difference).

trench

Makes sense, would be less potential wheelspin if engaging the new gear lower in the torque peak.

BT

Goggles Piasano

If you have Michelin tyres or Contis, they are nowhere near as good in inclement weather as say Pirellis. I have the Michelin Pilots (C7) package and have experienced touch and go situations in minimal snow conditions. On a previous car I had Michelin Alpin Winter tyres that really gave me a pause on a highway offramp doing no more than 30 kmph. The same day I had these tyres replaced with Pirelli Winter and Ice tyres which gave dramatic and superlative performance in all winter conditions. I just came back from Italy and in Rome came across a tyre shop that sold performance tyres, the Pirelli P7000 series will be the next set for my coupe next summer. This winter the Pirelli Winter and Ice tyres will be in place of the Pilots.
P/S To the European posters, Why are there so many diesel engined Mercs with such low displacements in Europe. Every CLK was a 200 (with the exception of one car) as were E class cars (200 cdi) and even S-class sedans. A class cars were as common as Fiats and those silly Renault "Smart cars". I only saw one ccoupe on the A-1 highway (this car doesn't seem to be very common in Europe as well). Furthermore what is the reason for so many mercs without number designations? I saw only one CL55 parked outside of the Rome Opera house, possibly Pavaroti's

DtS

Why so many diesel cars with small displacement? Simple! A gallon of gas costs ~$4 in most european countries. A gallon of diesel is commonly much cheaper (in most countires, Great Britan f.e. excluded). Plus the consumption for a diesel engine is much lower. So it's a question of fuel-pricing!

trench

Fuel is much more expensive there than here - notice nobody in Europe drives around in big-a$S SUVs. I also think that for some countries (the UK) there are tax advantages to driving a diesel.

Cheers, BT

vadim

Don't forget rather high taxes that are based on engine displacement.

steve s

diesel engines also tend to have gobs of torque, helps with moving people


did u hit a puddle of standing water? doesn't matter what kind of tire u had...u can always experience hydroplaning. my s-02 were a lot better than the pzero assy...some max performance tires do better in wet than all-season tires also.