winter tyres in the wet??

[chrisg]

Recently bought a W210 E320CDI (now remapped) that has Continental Contact tyres with the snowflake symbol on the rear only. This is my first torquey diesel so it may just be my driving but I keep spinning a wheel (or 2) when starting off and had the back end step out a couple of times on wet bends. I imagined that winter tyres would be good in the wet but am I wrong? If so, I'm going to replace them immediately! Pilot Primacy on the front - would this be a better wet weather tyre?? Waddya think??

 

[Shude]

Winter tyres are better in the wet, just look at the channels between the treads!

I'm thinking this may be a "driving style" problem rather than a tyre problem

 

[Rory]

That's odd, I would have expected them to be better in the wet. Are they very worn? Why doesn't ESP prevent it breaking away?

I guess if you haven't driven it on anything else, it's hard to guess the outcome (bearing in mind the remap).

You might be glad of winter tyres as the weather turns colder - they come into their own below about 7C.

Michelin Primacy are noted for comfort and long life, but not wet grip.

 

[BTB 500]

I keep spinning a wheel (or 2) when starting off and had the back end step out a couple of times on wet bends.

Wonder if your remap is an issue here (more power/torque than the ESP/ASR etc. is programmed for). Surely that would normally catch it before the tail could step out?

 

[Shude]

Wonder if your remap is an issue here (more power/torque than the ESP/ASR etc. is programmed for). Surely that would normally catch it before the tail could step out?

Well, the wheels do actually have to slip before ASR/ESP will do anything about it

 

[chrisg]

Re ESP - yes, the ESP does prevent (much) wheelspin in a straight line - light flashing - but as I said, putting even moderate power down on wet bends on my local country roads causes the back end to snap out enough to get the adrenalin going before the ESP or my supreme driving skill (!) catches it. I also drive a chipped 944 Turbo on the road and trackdays and I'm used to being very circumspect with that in the wet when the boost arrives but frankly I wasn't expecting the E class to be quite so hairy. General opinion that it isn't the tyres then? I wondered if the tread pattern designed to grip snow wasn't too good at dispelling water? For instance I also have a 4x4 on BFG MT (mud) tyres, which although superb in mud are known to be bad in snow 'cos (apparently) you need lots of small channels to grip snow but large deep channels (big block tread) to grip mud. Not sure if water behaves more like snow or like mud.

 

[BTB 500]

Well, the wheels do actually have to slip before ASR/ESP will do anything about it

Sure but the response is normally pretty much instantaneous with modern electronics. I know the ESP on my VW is supposed to react within a quarter of a wheel revolution, and ye olde ASR keeps my SL500 well in check in the wet ... I've certainly never had the back end snap out as described.

 

[chrisg]

Ah yes - but then does your SL500 have 500NM of torque???

 

[Doodle]

I'm with Shude on this one...

With the right attitude to throttle control, the C250 turns into a leery powersliding barge in winter months on the roads I drive (no traction control to speak of).

But being gentle with the throttle, and cautious with the big lump of torque, and all is well...not nearly so much fun though!

 

[grober]

torque in the wet problem.

Ah yes - but then does your SL500 have 500NM of torque???

I think thats your problem. I drive all year round with an allweather tyre on the back- Nokian WR. They do make the rear end slightly more skittish in the wet. I put that down to slightly different shoulder profile/stiffer side wall since the effect is most noticeable as the tyres roll on to their edges and I have found this can cause a sudden breakaway. The water dispersal properies of winter rated tyres are usually very good as has been stated. Your main problem is all that torque which is perhaps too much for the standard suspension/tyre size. You might find that its always going to a problem in the wet.

 

[Satch]

Suspect they are All Season tyres as opposed to Winter tyres. They should be OK in the wet though. How much tread depth is left?

 

[BTB 500]

Ah yes - but then does your SL500 have 500NM of torque???

Near enough. 470 Nm as standard, mine's running on V-Power 99 Octane with a less restrictive exhaust - which might nudge the output up a little. And as mentioned, it's not remotely tail-happy in the wet

 

[Ian B Walker]

Have you adjusted the tyre pressure at all?

 

[chrisg]

Interesting. Seems I just have to be more careful! Shame really. As to why C250 and E320 are more 'skittish' than SL, maybe poorer weight distribution? And yes the rear tyres are worn to about 33% of original tread so I'm sure that's a major contributing factor. Anyway my teenage son loves it (as a passenger) and thanks to ESP I can look like a driving God exiting roundabouts! Re extra power / tyre size, I presume increasing the tyre contact area is only going to make matters worse in the wet??

 

[grober]

wet n dry.

Re extra power / tyre size, I presume increasing the tyre contact area is only going to make matters worse in the wet??

Yes your probably correct on that one. Would help dry grip but might be a disadvantage in the wet as you say. Tread pattern and rubber mix probably more influential on wet grip than anything else.

 

[BTB 500]

Although the overall max. torque is similar, a remapped turbodiesel might deliver that power more 'abruptly' than a petrol V8 ... causing it to break traction? Gear ratios etc. might come into it too?

I'm currently considering a Vito 120 (with the 3 litre V6 diesel) for hauling my dogs around. That has 440 Nm as standard; bearing in mind it's RWD and I'll always be driving it 'unladen' (i.e. without a tonne of cargo in the back ) traction in the wet is definitely something I'm thinking about!

 

[Satch]

And yes the rear tyres are worn to about 33% of original tread so I'm sure that's a major contributing factor.

Indeed

http://www.mbclub.co.uk/forums/showthread.php?t=27750&highlight=tyre+tread+depth

As of last Sunday have my set of Goodyear Ultra Grip winter tyres fitted because although summer tyres are still legal, measuring between 2.5 to 3.0 mm tread depth, things were getting a bit lively in the wet. They have to go.