Speed Rating vs The Law & Insurance

[RoadWarrior]

Right... I've been researching this for ages now and I've still not found a definitive answer, so I thought I might as well try here:

 

Can you buy and fit tyres, legally and without invalidating your insurance... that have a lower speed rating than standard?

 

 

Basically, as part of my project I want to buy some ridiculous tyres that will achieve the following:

 

 

 

However, tyres like this only come with a maximum speed rating of S or T... yet my standard tyres are a W. The thing is, whilst the car is capable of doing mad speeds, I have absolutely no intention of doing +150mph!

 

As long as I stick within the limits of the tyre, surely there should be no issue? After all, I'm pretty certain winter tyres are around an H rating, which is below the standard rating(?)

 

 

If anyone has an answer, I'd really appreciate it

[langers2k]

I'd say yes if it's declared to your insurance company and they are happy.

[Auric Goldfinger]

Think  you need to run Tyres with the same or higher  speed rating.  Although you can legally run Winter/all season tyres with a lower speed ratoing

[KenONeill]

What I positively know.

 

As long as the manufacturer/importer are happy, and you retain the load index, you may fit tyres with a lower speed rating, but must inform your insurance company that you are doing so.

 

What I don't know of.

 

Any manufacturer, importer or insurer who will accept tyres with a lower speed rating than the OEM quoted maximum speed that the vehicle is capable of.

 

What would be legal regardless of the above.

 

Fitting your illustrated wheel/tyre combination when at a vehicle show on private land.

[sharkrider]

I go with the above... if insurance are happy, no isssue....

 

legally, as long as they are E marked you should be ok...

 

just be careful though, the T rating is only 118mph, s is even less!

its not just about max speed, its about the heat characteristics, I remember a mag putting V rated tyres on a hot hatch that has W's on and it ruined the handling, idea was it didn't get rid of the heat as well as the higher rated tyre....

 

HOWEVER my winters are H (130mph) and I have never had any issues with those. my standard fit were V (150) , and my track tyres are W's (168) (and my insurance company were happy and said "no charge as long as its a genuine skoda fitment size")

 

edit: looking forward to the car when finished!

[KenONeill]

S is 113mph - I remember this from back in a day when most cars used this speed rating.

[DAN@ADRIAN FLUX]

Hi,

If you need any assistance with insurance at all for a change of tyres then please feel free to drop me a line.

Regards,

Dan.

[AnotherGareth]

Can you buy and fit tyres, legally and without invalidating your insurance... that have a lower speed rating than standard?

 

Yes - the requirement for car tyres is that they are good for 70 mph.

[fatzy]

Yes - the requirement for car tyres is that they are good for 70 mph.

Sorry for interfering, I'm not English. But from what I can see is the regulation you refer to valid for "goods vehicle, bus and trailers".

I don't understand how you legally can install tyres with lower speed rating than the top speed of the car (in my country you must), UNLESS it is M+S marked. This is mainly for adopting to studded winter tyres, and they can have a 100 mph limit. I know that studs isn't legal in UK, but due to EU harmonization I assume the same regulations applies.

[RoadWarrior]

 

Yes - the requirement for car tyres is that they are good for 70 mph.

 

As fatzy said, that law only applies to goods vehicles, so has no bearing on mine :/

[gadgetman]

I thought you had to have tyres rated to the maximum speed the vehicle is capable of doing as a minimum?

[AnotherGareth]

See Regulation 27 (1) (a)

 

... a wheeled motor vehicle ... fitted with a pneumatic tyre shall not be used on a road, if the tyre is unsuitable having regard to the use to which the motor vehicle ... is being put or to the types of tyres fitted to its other wheels

which essentially means you aren't allowed to use certain incompatible types of tyre, (such as radial and cross-ply on the same axle, or radial on the front and cross-ply on the rear).

 

If you are not going to use the vehicle above the UK national speed limit then you only need to fit tyres that are capable of at least the UK national speed limit. This is why the UK MOT test does not fail cars that have tyre speed ratings below the maximum speed of the car, but does fail cars that have tyres with speed ratings below 70 mph.

 

In practice, though, because tyre load ratings are an absolute legal requirement, and because manufacturers make limited combinations of load and speed ratings for any specific size of tyre, you'll tend to only be able to go down a few speed ratings on any particular car.

 

For example, 205/45R16 (for a Mk1 Fabia vRS) is only available in H or above, (and only a small number of H-rated models are available in this size).