ceat_attack

I'm sure this has been asked many times but - my car has the staggered tires and unfortunately the tire shop in town cannot find the bigger size for the rear tires for winters and it would not be until next spring that I could get the proper tires for the car.

Is it ok to use the same size tire all around for winter tires? Does it affect performance or wear anything out more quickly?

Thanks!

CJG

4matic?

ceat_attack

yes 4matic C350

CJG

Then no. The fact they even suggested it tells me you need to find another tire shop.
Order from Tire Rack if needed.

dol4er

Check out your manual, it specifies all possible tire combos.

superangrypenguin

Absolutely you can run them all the same size in the winter.

superangrypenguin

?!?!

CJG

No, you can’t. Most tire shops won’t even replace just one damaged tire on an AWD car. If this shop is saying it’s okay, he needs to find a new shop. It is not okay.

superangrypenguin

Maybe you and I aren't interpreting the OP's post in the same way.

You can absolutely run 225 45 17's all around in the winter, or all around in general. It says so in the manual.

As per the OP.

" Is it ok to use the same size tire all around for winter tires? Does it affect performance or wear anything out more quickly?"

Now, I can see that perhaps you are reading the question as...can you run ONE tire/rim size different than the other THREE, then yes, I agree with you, the answer is "no".

CJG

On an AWD car? They have to be the “stock” size. A quick Google search will tell you that. Not to mention common knowledge.

Not trying to argue. Maybe I’m missing something.

superangrypenguin

Also, not trying to argue. Mercedes Benz Canada, and my manual both have told me that running 225 45 R17 tires/rim all around on a sport model W204 is OK, in winter or otherwise.

I disagree with you that a quick Google search will tell us what you are saying as well.

http://www.benzworld.org/forums/w204...5-45-17-a.html

https://www.google.ca/search?q=w204+winter+tires+same+size+all+around&ie =utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&dcr=0&ei=GeAUWv60Kd6DrgGs6bjIDg

CJG

>>Four-wheel drive and all-wheel drive vehicles are equipped with additional differentials and/or viscous couplings that are designed to allow momentary differences in wheel speeds when the vehicle turns a corner or temporarily spins a tire. However, if the differentials or viscous couplings are forced to operate 100% of the time because of mismatched tires, they will experience excessive heat and unwarranted wear until they fail.
Mismatched tires or using improper inflation pressures for all-wheel drive and four-wheel drive vehicles can also result in immediate drivability problems. Some Control Trac equipped vehicles in 4Auto mode may exhibit a shutter on acceleration and/or a noise from the front driveline and transfer case while driving. Some all-wheel drive and four-wheel drive vehicles may exhibit axle windup or binding while driving. Some four-wheel drive vehicles (manual or electronic shift) with a two-wheel drive mode may refuse to shift "on the fly" into 4x4 Auto or 4x4 High at highway speeds.

In this case "mismatched" would mean tires of the same size, since the car comes with staggered tires. What am I not understanding?
I suppose you're also going to tell me universal healthcare is better than what we have in the US? ;-)

shotgun_banjo

Same tire size all around is OKAY on all 4matics even though you have staggered tires when you buy your car. Dealership confirmed this, MB Canada confirmed this as well.

white46

Just adding for clarification.
Regardless AWD or 2WD, if the car came with staggered wheel setup and you want to run the same size tires, you need to buy the same size wheels as well.

CJG

Again, I don't understand why. Can anyone explain this? If this is the case you could run the same size tires on all four all the time and have the ability to rotate them. I've owned at least 15 AWD/4WD vehicles and have always had to run the OEM tire size. As I stated before, in the event of a tire failure most shops will not even replace one tire unless the others are basically new. In larger chains such as Sears they are prevented from doing it in any situation.

edgalang

You can absolutely run them all the same size. You can even run a different size as stock assuming they are all the same. The problem with 4-Matic/4WD cars is that you cannot have a big delta in tire CIRCUMFERENCE between the fronts and rear unlike 2WD cars.

Alfadude

I think some of the confusion has to do with definition of "size of the tires". As long as all four tires are the same circumference you are good. In the Mercedes stagged set up the fronts are 225/40/18 and the rears are 255/35/18. That difference in the aspect ratio makes for the overall circumference of the front and rear tires to be the same, or at least very close enough that it doesn't make a difference. I don't remember what tolearnce might be OK, I think it might be about 2% difference max. ,It is a function of the aspect ratio and the width. What you would not want to do is have two tires that are 225/40/18 and two that are 255/40/18, as that sidewall on the 255 tire would be taller than the 225 tire. That would be enough mismatch that you would have problems and that is why you do not want to replace one tire on an axle with a new one and then have the one on the other side extremnely worn, as that would cause the circumference to be different enough to cause a problem.

ceat_attack

I ended up ordering the staggered fit with 225/45 R17 for front and 245/40 R17 for rear.

My owners manual doesn't seem to make a lot of sense - which I will stop by Mercedes today to clarify with them. It seems as though everyone has a different opinion. The tire shop I ordered from said in a 16" rim their system says all same size is ok, but once in 17" rims and up staggered is being recommended. My tire shop also said all the sites they checked for tires recommended staggered fit. Although in the manual it seems to say that you can have same size all around ( not overly clear though)

I will be doing a lot of mountain driving this year, so safest drive is important.

Still confused as to what is best however.

Alfadude

I believe the stock OEM 17" rims use all the same size tires and if you have the 18" rims, that is when they fit stagerred widths from the factory. Not a problem at all to use four of the same size tires. However, you would want four that are the 225 width and not four that are 255 width as they would cause rubbing in the front.

ceat_attack

Yes you are right. I went into Mercedes and they recommend the same all the way around for winter, not staggered as both tire shops informed me I should be doing and ended up buying annoyingly.

Mercedes told me my car comes with a factory 18" rim which would be staggered for summer tires and in the winter they recommend switching to the 17" rim with the same tires all way around. However, they said its not a huge deal that mine will be staggered, just a little less control in the snow.

I guess I am still confused then as to why tire shops tell you you need the staggered set if it's not what Mercedes recommends..

superangrypenguin

Most tire shops are not aware of specific Mercedes recommendations.

95_993

As most have said, same size 225s on all four corners even on staggered rims is totally fine on 4Matic sport.

225 specs easily both front and rear wheel widths. In fact, next time I replace my winter tires, I am going with 225s alll the way around.

c300white

The reason the tires have to be same “circumfence” on each wheel is is the diffs do not experience unusual wear in a 4 matic.

But same circumference is not same as “same size” .

Staggered fit in summer tires is for handling reasons - the wider rears will hang on longer than the front in a sharp turn - avoiding oversteer. But in the winter you are less concerned about that. The 45 series front have similar circumference to the bigger 40
series rear.

For winter tires , same size = same circumference - so that is ok - what you give up is some of the handling characteristics at the limit - so don’t take it to the track

this is also the the reason you cannot just replace one worn tire with a new one - and they should be replaced in pairs on the same axle ... so circumference matches !

superangrypenguin

Thanks for the explanation.So using: https://tiresize.com/calculator/

225 45 17 has a circumference of 78.4"
245 40 17 has a circumference of 77.6"

Guess that's close enough then for the factory staggered setup.