MO Tyres

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Druk

Gone but not forgotten - RIP
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Friend of mine has been told by a tyre fitter that unless a tyre (on a Mercedes)has an MO rating then it may invalidate the cars insurance.

Any truth in this?
 
Would be interesting to see if the Hankooks etc. that are now Factory fitted are MO spec or if that is just the domain of the premium tyre companies.
 
Nope, as long as they are of a size and rating which is fitted as standard and have the correct EU approval markings then they will be fine.
 
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Mercedes Original (MO) tyres are 100% optional. No insurance implications whatsoever.

The size and rating of the tyre must of course be as per the owners manual, otherwise the insurer must be notified regarding any deviation from the original specifications.

But MO is not an issue.
 
Much discussion as to whether MO tyres are in any way different to their non MO equivalent. One suggestion was that they had a slightly more compliant tyre compound mix to give a quieter ride at the expense of wear- I somehow doubt it. There are certainly no insurance implications provided they are to the same speed/load rating.
 
The only difference I'm confident of is MO tyres are selected from those that comply with much tighter QC limits. As advised by Michelin tyre development manager.
 
My own experience with manufacturer-approved tyres (not just Mercedes) is that they all seem to have the exact same colour rings in the same location.... while non-approved tyres seem to come with coloured rings all over the place.

This is based on two sets of manufacturer-approved tyres and two sets of non-approved tyres, so admittedly it is not 100% conclusive (ie it may have been a coincidence), but it's enough to make me believe that this is most probably the case.

The importance of having the coloured rings in the same location is that one of these rings is crucial to ensure there is no tyre drift at the front (pulling to one side).

There may be other differences but none that I could notice.
 
Would be interesting to see if the Hankooks etc. that are now Factory fitted are MO spec or if that is just the domain of the premium tyre companies.

My GLC came with factory fitted Yokohama tyres.

Blackcircles lists them in a MO variation (they're 235/60 R18 103V).
 
I contacted my insurer Aviva about upping the rears from 285 to 295, due to more availability and being a bit of a poseur, and they said they weren't interested in tyres for insurance purposes.
 
I contacted my insurer Aviva about upping the rears from 285 to 295, due to more availability and being a bit of a poseur, and they said they weren't interested in tyres for insurance purposes.

Presumably following the backlash over increased premiums for winter tyres, they are now (sensibly) looking only at different/larger wheels but not tyres...

On a related note, the need to notify the insurer regarding modification is one thing, but the driver is still responsible for ensuring that the vehicle is safe and roadworthy at all times. The fact that the insurer is not interested in tyres does not give drivers a carte blanche to fit whatever tyres they wish... in the event of a claim, having incorrect tyres fitted to the vehicle can in principle be used by the insurer to avoid pay-out if they can convince that the car was unsafe or not roadworthy (though they will probably require something more substantial than an increase from 285 to 295).
 
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As long as load and speed ratings are still as stipulated by the manufacturer and the tyre size to rim width is within the tyre manufacturer's specifications......
 
Just had this same question. Merc dealer was telling me that I had to replace the GL's 295/40/R21's with PZero's MO marked for £345 a corner.....bit of research and a chat with the insurance company resulted in that being complete tosh. Ordered a couple of Toyo Proxes SUV XL (exactly the same ratings) for £162 each fitted from Oponeo.....had these on my previous RRSport and was very pleased with them. Current PZero's have been lunched in 15k, which given it's a sedate barge I find a little disappointing :(

When I did get hold of a decent dealer, they told me the 'MO' was just a marker that they were an OEM product that had been tested by Merc and were 'approved'. Part of it is marketing from the tyre co's.....how many people will just order the ones that say Merc (or BMW) because they think that's the requirement.
 
I had an exchange of emails with Tony Bones of Wheels in Motion when I was needing new summer tyres in April of this year........I copy below an extract from that exchange. I do not believe this email is confidential and I further believe that Tony would not make such a statement if he was not confident that it is factual.

Hello Michael
You need to stick with the MO fitment regardless of what’s said online because there is structural differences between the MO and non MO. As for cost we are not the cheapest at £170 each all in but we do use the best machinery in regard to fitting/ balancing etc..... As for the chassis it’s hard to quote up front since we don’t know what if anything needs correcting, needless to say an image of the chassis costs £30+ vat and from that we can offer an absolute price.
I hope this helps
Regards
Tony@ wim

Mic
 
The structural differences referred to could be how well the tyre has been manufactured, the compliance with stricter QC limits, as confirmed by the Michelin chaps I was speaking with. The concentricity, run-out and balance are all measured and graded by colour banding. MO tyres achieve a much tighter compliance than non-MO labelled examples. Generally these tyres are no more expensive as they are manufactured and tested the same as all others. In very rare instances marque specific tyres can be of special compound or structure but as these will be produced in much smaller lots they will be more expensive.
 
Just to clarify while there is a valid question as to how MO tyres are different to no-MO - if at all - but clearly any tyre officially sold in the UK that meets EU regulations and the manufacturer's specifications in terms of size, load, speed rating etc, is both legal and safe to use.

The only real question is simply whether there is any actual advantage in buying MO tyres... not if it is illegal or unsafe to drive on non-MO tyres as such.
 
Just had this same question. Merc dealer was telling me that I had to replace the GL's 295/40/R21's with PZero's MO marked for £345 a corner.....

I hope mercedes have good solicitors, as the Pirelli P zero is probably the most lethal tyre in the world in wet weather. Just shows MO is a joke and tyre makers must pay mercedes and get good marketing out of the deal.

Maybe this missed the suffix RON on their MO Pirelli's ? :dk:
 

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