MOT Failure Advice - Tyre Types

czajunia

Hi, could I please get some advice on an MOT failure due to "tyres with different structures fitted to the same axle"? 

They were not identical tyres. Both were the same sizes of course and both were radial tyres from what I can see on the side of the tyre. One was rated 83V the other one was 87V. One of them, however was Bridgestone All Weather tyre and the other one was just a normal Summer tyre.

Is it a reason to fail an MOT? (It wasn't an advisory it was a failure.) Are there different types of radial tyres that would classify as having different structures?

Also, just to clarify, I'm not asking if it's recommended to mix different tyres but whether it is illegal and if that's a reason not to pass an MOT. Thank you very much. 

sheslookinhot

What was the failure reference number specified on the Fail notification ?

czajunia

It was 5.2.3(c) 

tacpot12

This link is the MOT Inspection Guidance Section 5:  MOT inspection manual: cars and passenger vehicles - 5. Axles, wheels, tyres and suspension - Guidance - GOV.UK (www.gov.uk)

It confirms that radial and cross-ply tyres cannot be fitted on the same axle, but two different brands of radial tyres (even with different load ratings) should be fine. 

I would go back to the MOT station and ask them to show you which tyre is not of radial-ply construction.

fatbelly

I think that code is where radial and cross ply are mixed. As you say though, not ideal to mix all-weather and summer tyres.

czajunia

Thanks for the prompt reply.

I was thinking about going there actually but first wanted to make sure it was OK to have different weather type tyres on the same axle. They said they had to replace the tyre because it was a winter one (which is not accurate to start with as it's an all weather tyre) and the other one was a summer one and that was a different structure.
I thought that was BS and after doing some research I couldn't find anything on the gov MOT website (and the Internet in general) regarding weather type tyres but I'm no expert so I thought maybe I was missing something. 

Just for the reference this is the tyre they replaced (apparently a winter one according to the garage):



And this is the one they left on the car:


Am I correct thinking they are both of the same type? Again, I'm fairly certain they are but wanted to make sure before I go to the garage. 

czajunia

fatbelly said:

I think that code is where radial and cross ply are mixed. As you say though, not ideal to mix all-weather and summer tyres.

I am aware it is not ideal and will be replacing them with the same tyres soon. Having said so, I'm sure they are more than adequate to be stuck in London traffic. :-) 

I just wanted to clarify if it was an MOT failure as it feels like the garage either doesn't know what they are doing or they just try to upsell their MOTs. 

offroader

Radial and steel belted tires have different constructions and uses, and each has its own advantages and disadvantages:

• Radial tires

  These tires have steel belts that run at a 90 degree angle to the tread center line. They are designed to provide a smoother ride and have the following advantages:

  • Better comfort and control: Radial tires have a larger footprint and are designed to provide a smoother ride on different surfaces.
  • Better traction: Radial tires have more flex, allowing more ground contact and better traction.
  • Better fuel economy: Radial tires are more fuel-efficient.
  • Run cooler: Radial tires run cooler at highway speeds and under load.
  • Longer lifespan: Radial tires have a longer lifespan.
  • More resistant to punctures: Radial tires are more resistant to punctures.
• Steel belted tires

  These tires have a more rigid inner material that bonds with the tread. They have the following advantages:

  • Higher inflation pressures: Steel belted tires allow for higher inflation pressures.
  • More load carrying capacity: Steel belted tires have more load carrying capacity.
  • Lower rolling resistance: Steel belted tires have lower rolling resistance.
  • Higher speeds: Steel belted tires can handle higher speeds.
  • Casing durability: Steel belted tires have casing durability.

czajunia

Thanks. What about "steel belted radial" tyres? (pls refer to the picture above). That's the one they left on the car. Is that another type of tyre construction or does it fall to the same category as "steel belted"?
They actually replaced the other tyre which was a normal radial type with another radial one (just a summer one). 

So if anything (providing that steel belted radial tyres have different structure than normal radial tyres and they cannot be used on the same axle) they should have replaced the one they actually left on the car with the new radial one. And it all had nothing to do with weather rating after all. They just replaced the wrong tyre.

EDIT: Think I just found an answer to my question on the MOT website: "Steel and fabric radial-ply tyres are considered to be the same structure."
So it doesn't look like they have different structure after all.