225 snow tires fits on the oem 18'' wheels?
Thanks in advance!
This is because in the Owner's manual they specifically call for 225/40/18 for both front and rear for winter.
This raises two questions:
1. What rims do they have in mind for the rear
2. How do they plan to compensate for the different wheel diameter and error in speedometer.
I may call Mercedes of North America today, then I will post the answer.




Even better, why not get cheap wheels, the cost of switching over and the amount of damage likely to incur at each switch over to your wheels is not worth the savings, the wheels pay for themselves after a few seasons of change over and then you can just switch them out yourself, or pay a lot less to have them swapped on rims. They you can go 8" wheels all the way round!
Also, with this being an issue and Mercedes being the Engineering heaven that they are, they probably have a "secondary protocol" that we don't know about, to account for this error.
I want to get this info from them, there is probably a winter wheels mode that changes the readings everywhere.
As far as the rest, maybe they will suggest to buy a second set of front wheels, let's see.
I agree about not wanting to stretch the tires to the max and not wanting to repeatedly take the tires off, vs having two sets of wheels.
I disagree about using 235 series tires.
The importance of using narrow winter tires is not well understood. One size down changes the pressure on the contact patch quite enough to make the difference between ok behavior to great behavior in snow. I am willing to bet that Mercedes posted 225 and not 235 based on calculations and they are usually right.
https://tiresize.com/comparison/
The importance of using narrow winter tires is not well understood. One size down changes the pressure on the contact patch quite enough to make the difference between ok behavior to great behavior in snow. I am willing to bet that Mercedes posted 225 and not 235 based on calculations and they are usually right.
Last edited by nobbyv; Oct 4, 2016 at 12:43 PM.
235/40/18 has a radius of 235x40/100+ 228.6= 94+ 228.6= 322.6 mm. The increase per radius is 322.6-218.6= 4 mm
The difference of diameters is 645.2-637.2= 8 mm
Edit:
I just called them. They refer to the dealer as to which tire works with which rim. Maybe I got the wrong rep and have to try again.
As far as menus for different diameter, there are none.
So what remains is I will check whether the wis wiring diagram show that there is such thing as a distance pickup on the transmission, or the distance is via formula and averaging data from all 4 wheel speed sensors. I expect the latter.
If this is the case then the formula may offset the difference in the diameter of the fronts, to an extent,
Last edited by Vladds; Oct 4, 2016 at 02:58 PM.
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I just ordered Replika R170 8.5 X 18 ET 43 wheels with Nexen Winguard Sport tires 235/40 R18 V 92 and they will be just fine. They will be 8 mm closer to the fender but clearance will be ok.
With TPM sensors $1765 CDN including tax and shipping from 1010Tire.com
Yes not an expensive tire but of the 121 days between Dec 1 and April 15 I am only around 46 days so buying expensive tires name brand is a lousy investment. When they are 6 years old they might have 12000 km on them


This is because in the Owner's manual they specifically call for 225/40/18 for both front and rear for winter.
This raises two questions:
1. What rims do they have in mind for the rear
2. How do they plan to compensate for the different wheel diameter and error in speedometer.
I may call Mercedes of North America today, then I will post the answer.
BA 235/40 R18 95 V XL
M+Si15
8.0 J x 18 H2
If you go the same tire on both axles (BA) then you can rotate them front to back season to season which you cannot do with the staggered set up.
So it's some kind of formula that accounts for differences in wheel rpm while turning and probably diameter differences due to tire pressure changes., in order to determine from the 4 signals vehicle speed and distance travelled.
I'm just concerned about burning them up too quick.


So it's some kind of formula that accounts for differences in wheel rpm while turning and probably diameter differences due to tire pressure changes., in order to determine from the 4 signals vehicle speed and distance travelled.
That said they do have a passive system that starts with manually setting tire pressures. When you start out you reset the monitoring system. From that point forward it compares wheel speeds off the ABS sensors in the wheels. When one tire losses air its diameter shrinks and the wheel has to go faster to keep up with the other three and the sensor sees that and alarms.




Back in the day when tires were not directional we cross rotated them.
Your choice by all means. I have just found that whether it was either of my W124, my W211s, my W212, R170, R172 this was good practise.




Even out the rate that they wear.
But I find that the rears wear more than the fronts.
FWIW I need a new set of 'summer tires' as I was only able to get 10,000 km out of the stock OEM Contis
Wore them down to the wear bars (front and rear). But my winter tires that are now on for the 3rd winter look almost new.Clearly my driving habits in the winter (not wanting to wear down the winter tires) has an impact on the longevity of the tread



Even out the rate that they wear.
But I find that the rears wear more than the fronts.
FWIW I need a new set of 'summer tires' as I was only able to get 10,000 km out of the stock OEM Contis
Wore them down to the wear bars (front and rear). But my winter tires that are now on for the 3rd winter look almost new.Clearly my driving habits in the winter (not wanting to wear down the winter tires) has an impact on the longevity of the tread






235/40/18 has a radius of 235x40/100+ 228.6= 94+ 228.6= 322.6 mm. The increase per radius is 322.6-218.6= 4 mm
The difference of diameters is 645.2-637.2= 8 mm
Edit:
I just called them. They refer to the dealer as to which tire works with which rim. Maybe I got the wrong rep and have to try again.
As far as menus for different diameter, there are none.
So what remains is I will check whether the wis wiring diagram show that there is such thing as a distance pickup on the transmission, or the distance is via formula and averaging data from all 4 wheel speed sensors. I expect the latter.
If this is the case then the formula may offset the difference in the diameter of the fronts, to an extent,




