paul-the-limey

Hi Luke,

I just purchased a set (4) of a brand of tire that is only available in Europe (I think). Here is a link to a web site that shows the tire. They are called Continental Premium Contacts. I have a C240 Auto running stock 205/55 R16 91V tires:

web site: http://www.conti-online.com/generato...master_en.html

I have a problem. The car seems to wander when at speeds of 80-100 mph. Its quite bad. Like being caught in a cross wind. I had the problem initially when I replaced the fronts to the premium contacts as the rears were still SportContacts. I thought it might be because of the mixing of tyres. Now I have replacesd the rears to premium contacts as well and the problem is now worse!! THis is apparently an MB recommended tire and has won many +++ ratings on variouis web sites in Europe.

I just had the geometry checked on the car as well as the srings and shocks. These are all stock items and are all fine according to MB. The car was fine before I got these tyres. I also had the car on a rolling road at the tyre shop and they said the tyres were well balanced and not out of round.

What am I to do?? My pressures are 33F and 35R.

I really don;t want to have to dump the tires. They cost me over $500 for the set (4). Can a change to the pressure help do you think?

I really would appreciate your taking a moment to look at the web site and comment. They are meant to be some fantastic tire that "works like a cats paw". Mine work like a cats a*se at the moment. I'm wondering if this is why they are so bad. I also wonder if they need a special pressure but can't find anything on Continentals web site.

I quote from the web site:

The bionic ContiPremiumContact means safer braking

The new ContiPremiumContact works like a cat's paw as it brakes: it widens, to ensure safe transmission of greater forces to the road. The tyre is therefore able to transmit braking forces more efficiently than a conventional tyre . Under normal driving conditions the tyre remains slim to provide protection against aquaplaning.

jbcritch

Are they unidirectional but have been put on backwards????

Luke@tirerack

actually, we do have that tire over here ..... but, it is reasonably new to us and I have not had an opportunity to drive them yet .... I would suggest trying different pressures to see if you can cure your problem ...... yes, it could be that easy .... many tires have different characteristics when it comes to tramlining which is what you are experiencing and pressure can have a dramtic impact of that issue

paul-the-limey

jbcritch - Hi, I checked the tyres and they all say "Outside" on the outer edge.

Luke, Thanks, I will try different pressures. Do you have a suggestion. Lower or higher? I was thinking of 36F and 38R. What do you think? Will this make braking in the wet dangerous? Some threads suggest higher at front. Maybe I should try 38F and 36R?

Cheers,

Paul

paul-the-limey

Hi.

I have also noticed about a 2mpg improvement in the fule consumptioin with these tyres comapared to the ContiSports I had. I wonder if this is in some way related? Perhaps I need to decrease my pressure to bring the MPG back in line which may also fix the wandering problem.

paul-the-limey

Just a quick update: I tried 39R and 37F (psi) and it made matters worse than ever. I then tried 31.5 both F&R and it seemed better. Is 31.5 F&R too low to be safe?

I am currently in dialog with Contental in Germany and have requested that they replace the Premium's with SportContact tires. I will let you know the outcome but I'm not holding my breath!!

Luke, Are you sure you have these tires in the US? I have seen "Premier" but not "premium". The premiere seems to have a totally different tread pattern to the "premium" tires that I have (see URL above and compare it to the URL below):

US Premier tires Link

Harris

Are your tires DOT approved? Some insurance companies do not cover it if you are in an accident.

Luke@tirerack

try the Mercedes recommended pressure for your car of 28 front and 32 rear

paul-the-limey

Hi.

Inside my fuel filler cap it says:

Normal = 30F 33R
High Speed / heavy load = 33F 41R

When I complained to Continental they suggested 35F and 39R

So you can see my problem.

Luke@tirerack

I was basing my recommendation on a US spec c-class ..... lower pressure tends to lead to better ride quality that's why I suggested the 28 front ... it would probably yield less tramlining which is what you are looking for

paul-the-limey

Hi,

Continental have kindly agreed to swap the tires for SportContacts and they will then do some testing. They say they have had no reports of this in the past so maybe I just got a bad set of tires?

They will let me know the outcome of the tests.

Paul