replacing 1 tyre only

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Barbel7

New Member
Joined
Aug 16, 2019
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1
Location
England
Car
Mercedes ml300 blue efficiency
Can I replace 1 tyre on my Mercedes ml 300 4matic 2012 plate
 
Of course you can , but should you? As indicated the post above it depends on what state the others are in, more info needed
 
It may benefit the diff if you replace both on 1 axle.
 
I just replaced the front two, due to nearside wear from cracked rim,, got it tracked and sold offside still with 4/5 mm tread for £50. Result.
 
As long as the tyre is the same size and construction as the other tyre on the same axle and is as specified in the manual, then yes you can. Doesn't have to be the same make, tread pattern or tread depth as the other tyre(s). However, I think it's best practice to have the same tyres all round and change them in axle pairs when practicable.
 
As long as the tyre is the same size and construction as the other tyre on the same axle and is as specified in the manual, then yes you can. Doesn't have to be the same make, tread pattern or tread depth as the other tyre(s). However, I think it's best practice to have the same tyres all round and change them in axle pairs when practicable.
Sorry but I don't agree, I think it is essential to have matching tyres on the same axle and not just best practice.
 
In an episode of Wheeler Dealers (I think the DB7) Mike complained it felt very skittish and was a bit all over the road during his test drive. Edd spotted different tyres side to side on the front, changed them and it tracked straight and true.

Legal? Yes, with constraints.
Desirable???
 
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Sorry but I don't agree, I think it is essential to have matching tyres on the same axle and not just best practice.
I don't agree either, but that is the case. As Stratman says, there may well be problems as a result, but it is permitted (if not sensible) to change just one tyre.
 
Being 4matic, what are Mercedes guidelines on having different tread depths on the same axle. Many have a tolerance of 2mm, but that may have changed now.
 
I don't agree either, but that is the case. As Stratman says, there may well be problems as a result, but it is permitted (if not sensible) to change just one tyre.

It's confused by the situation with viscous coupling AWD cars and cars with clutched sensing systems.

AIUI:

(1) If you have a viscous coupling rather than a traditional centre diff then you need to keep all tyres the same.

(2) If you have a clutched centre diff then you may have the same situation as (1) depending on the AWD strategy/settings used internally.

(3) if you have a plain ordinary centre diff then same rules as 2WD car.

(4) if you have a less-plain diff such as a Torsen diff then some people care (go with (1) and (2)) and some don't (go with (3)).

The problem is that manufacturers are not transparent about the drive systems and the advice in to change all tyres is becoming a convenient (for internet, tyre specialists, and dealers) statement.

The internet opinion is increasingly going with treating the situation as mandatory and unquestioned that you *must* keep all tyres the same on any sort of AWD / 4WD but *my view* is that this is because the basic simplistic advice relating to the systems in (1) and (2) is asumed now to be universal.
 
Well, if a typical wheel and tyre has a diameter of say 600mm and the difference from new to illegal tread is 6mm (12mm on diameter), the issue is whether the drivetrain can cope with a 2% difference between individual wheels. I would have thought this would be a reasonable amount of tolerance to manage given that the transmission has to cope with such as a 10m radius 90 degree corner where the outside wheel travels about 13% more distance than the inside wheel.
 
Well have been nosing on the web I found this on Wiki..

Permanent 4Matic four-wheel drive remained, with one-speed transfer case (no low range), center limited-slip differential and four-wheel electronic traction system (4-ETS). In most countries except the U.S., an Off-Road Pro package with center and rear differential locks, 4-ETS, two-speed transfer case with reduction gearing, and adjustable ground clearance was available

So reading that there is an lsd in the middle of the drivetrain, I'd say that all tyres have to be with in 2mm of each other... Plus the system was developed by Puch... they have a reputation for being very good, but also fussy about differences in the tread depth
 
yes
 
Yes you can. I would either buy a part worn with no repairs/damage of the exact same size/brand which has similar depth OR replace both and keep the good tyre as a spare in case it is required for a similar instance.
 
Over here in France You MUST have matching - not similar, not almost the same - on the same axle.

With all 4 wheel drive vehicles (especially ones with electronic aid) it is advisable to have matching tyres all round. After all you buy a 4x4 to get extra grip and traction don't you? So why would you compromise that by not having matching tyres ?
 
So reading that there is an lsd in the middle of the drivetrain,

My understanding is that the 4Matic setup involves a clutch in the centre diff setup.

(It's always worthwhile being wary of differences in the actual implementatin between different car types. The manufacturers are quite capable of taking a branding term such as 4Matic and applying to different AWD / 4WD systems used in different model ranges.).
 

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