1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

w163 winter tyres, size conversions and ESP

Discussion in 'Bodywork, Tyres, Wheels & Trim' started by Valko, Dec 1, 2011.

  1. Valko

    Valko New Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Dec 1, 2011
    Location:
    London
    Your Mercedes:
    ML/2004/270CDI
    Hello,

    another tyres question, Mercedes recommends only one 17 inches tyre size for my w153 ML 270CDI: 255/60R17

    we all now the narrow and the higher is the winter tyre is the best, based on this I have the following questions:

    1. Is it ok to use 235/65R17 size - bear in mind that ALL radius and diameter lenghts for 255/60R17 and 235/65R17 are 100% the same the only difference is tyre width (see http://www.miata.net/garage/tirecalc.html ), Mercedes mention something about ESP not working fine with different sizes?

    2. How far from recomended 255/60R17 I can go (anybody here used different winter tyre sizes?), for example I really would like to have 225/75R17 as proper high and narrow winter tyre, is anybody used it on ML, is it fine to do that? The radius for 255 is 14.5 inches the 225 will be 15.1 - means half inch higher.

    thank you for your help
     
  2. oigle

    oigle Senior Member

    Messages:
    3,045
    Likes Received:
    357
    Joined:
    Mar 15, 2005
    Location:
    Redcliffe, Queensland, Australia
    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    I have used 235/65/17 on mine for last 85000km. In fact the size works better on the car than the original. Wears better and steers better. I'm talking AT tyres here, suitable for normal conditions but haven't used tyres specifically designed for snow/ice - doesn't happen here!!
     
  3. Naraic

    Naraic Moderator

    Messages:
    10,330
    Likes Received:
    942
    Joined:
    Mar 4, 2010
    Your Mercedes:
    2005 CL500.
    The taller tyre will have a greater circumference...the gearing will change....but otherwise everything will work.
     
  4. OP
    Valko

    Valko New Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Dec 1, 2011
    Location:
    London
    Your Mercedes:
    ML/2004/270CDI
    thank you Oigle I am going for 235/65R17 winter Vredestein Wintracs and looking forward for our Christmass snow :), I bought the Merc this summer and have never driven 4x4 in snow, although I personally think the tyres are more important then the drivetrain, I remember some past winters with one foot snow and my Golf II was overtaking all 4x4s in deep snow with good tyres :))
     
  5. oigle

    oigle Senior Member

    Messages:
    3,045
    Likes Received:
    357
    Joined:
    Mar 15, 2005
    Location:
    Redcliffe, Queensland, Australia
    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    the 235/65/17 are almost exactly the same circumference as the originals, so no problems there.
     
  6. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    34
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    Seems the 235/65/17 are a good call then.

    If different radius tyres were used, the most likely problem would be with the auto transmission, if fitted.
    The ESP should be fine as long as all 4x have the same radius.
    The auto box however would not be happy about it, and would throw up 'gear ratio implausible' fault codes.
     
  7. oigle

    oigle Senior Member

    Messages:
    3,045
    Likes Received:
    357
    Joined:
    Mar 15, 2005
    Location:
    Redcliffe, Queensland, Australia
    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    That's an interesting comment, Alex.
    Why would different size tyres cause an issue, assuming of course that all 4 were the same? How would the auto box know? Be just like going slightly uphill or downhill from a load point of view and gearbox would not know cars actual speed versus its indicated speed.
     
  8. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    34
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    The transmission compares engine speed, 2x internal speeds and vehicle speed.
    It obviously expects certain gear ratios to give certain ratios between these various RPMs.
    People swapping diffs, or auto boxes with different internal ratios come up against this problem.
    A certain change in tyre radius will be OK, but it does not take a big change to run into these issues.
     
  9. oigle

    oigle Senior Member

    Messages:
    3,045
    Likes Received:
    357
    Joined:
    Mar 15, 2005
    Location:
    Redcliffe, Queensland, Australia
    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    Yes, I appreciate that odd tyres or one diff ratio being changed etc would def create issues. Cannot see where putting 4 new tyres of a larger/smaller size would cause any issues at all in any of those areas. Nothing in the vehicle can sense the cars actual road speed, so no conflicts. Speedo and other speed sensors would still indicate similar speeds.
     
  10. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    34
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    The transmission is electronically controlled, as you know, and relies on important data to help it control its shifts and adapt them over time.
    It uses 4x speeds for this, engine speed, input speed, an internal speed from one of the baskets, and an output speed derived from the ESP (or whatever system handles vehicle speed data).

    If we stick on wheels of a much smaller or larger circumference the tranmission control will not see the correct correlation between the first 3x speeds and the output speed - hence the ratio fault code.

    Just how far out the tyre sizes would have to be to cause this issue I do not know.

    EDIT: Cancel all that, I am wrong! Of course if all tyre sizes are the same the vehicle will know nothing, just think it is going faster/slower than it is!

    SORRY!
     
    Last edited: Dec 3, 2011
  11. oigle

    oigle Senior Member

    Messages:
    3,045
    Likes Received:
    357
    Joined:
    Mar 15, 2005
    Location:
    Redcliffe, Queensland, Australia
    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    We all get brain fade occasionally!! I was beginning to think I had missed something there. Thanks mate.
     
    Last edited: Dec 3, 2011

Share This Page