Tyre Speed Rating Query

[delta925]

I have checked a couple of sites and found

H rated tyres are suitable upto 131mph.
V rated tyres are suitable upto 149mph.
W rated tyres are suitable upto 168mph.

Looking here
http://www.malaysiaminilover.com/audi-a4-performance

my Audi A4 1.9 tdi 115PS has a quoted maximum speed of 124mph.
while
a 2.8 V6 30V petrol has a quoted maximum speed of 149mph
a 1.8T petrol petrol has a quoted maximum speed of 144mph

I have Audi 16" alloy wheels fitted when new with 205/55/16 tyres that are W speed rated.

If I had 15" (steel?) wheels the tyres would be 195/65/15 or 205/60/15 both with a V speed rating

I can understand why W rated tyres are specified to cover all models as I guess the 16" alloys were standard on the high performance models.

Provided the load rating of 91 is the same is there any reason why I can not fit V rated tyres of the same size (205/55/16) since they are rated 25mph above the theoretical maximum speed of my model, not to mention over double the UK legal limit of 70mph.

In particular would a fastidious MOT tester have any reason to issue a fail if two V rated and 2 W rated tyres were fitted?

[Bratty]

I can quite catagorically say! that having experienced (the opposite from your exp) from the German (very precise and quite frankly ****) system, you should have absolutely no probs (or are you currently in negotiation with a knoob MOT testing center?), here all cars have a max speed stamped in there log books and as long as your tyres cover this limit there is no problem (exception winter tyres where you must display (or have an electronic limit warning) sticker.

Dunk

[alogbe]

It isn't clear what Bratty means by "here" - is that in Germany?

I don't know anything about the UK rules, but in France (where I live) the minimum speed rating for a tyre is the one that was declared in the manufacturer's homologation specs. In my case that means a 'Y' tyre, even though a 'W' would theoretically be more than enough for the car's declared maximum speed.

When I queried this I was solemnly warned by the CT (French equivalent of the MoT testers) not to risk it, so I didn't. In any case the difference in price was trivial, although I had to shop around a bit to find the 'Y' version of the tyre I wanted.

[Bratty]

In Germany (which is very strict on rules and regs!) The vehicle needs to be fitted with tyres that (At Least!!) cover the Manufacturers "Claimed" Max speed for that SPECIFIC! model (as laid down in your cars documentation V/Max). Have a look on your vehicles "Certificate of Conformity" section 44, If your test center gives you any hassle waive it under their nose and get them to explain

The exception is winter tyres which can be of a lower speed rating as long as the max speed limit for the tyres is displayed on the instument cluster (ie.Sticker or speed limit set in car computer).

I have just bought a car from the UK which had a new MOT (perhaps dodgy) that does not even have the correct width tyres on the rear axle! Find it difficult to believe that UK MOT center would be tougher than a German TÜV..

But its down to individual inspectors I suppose?

Dunk

[delta925]

The reality is UK MOT test stations vary widely, and that is before any ' friendly relationships' between a tester and a used car trader.
I know someone who bought a car with a new MOT that had a serious brake fluid leak where fluid soaked the shoes such that no way could the car pass a MOT brake test plus the tester should have seen the area wet with fluid.

Generally in the UK avoid the fast-fit chains as they are looking for easy work like exhausts and suspension a well as tyres.

Once having bought a car that had a loss of power I went to a centre as they had a tune-up offer. Later I had a call to come and see a major problem. When I got there all the wheels were off - I booked in for a tuning check remember - and they told me I needed front discs and pads and rear drums and shoes because all were scored and all wheel cylinders changing. All that was obvious was one wheel cylinder had a very slight leak. The MOT was by then 3 months old and the car serviced at the same time. I simply made them put the car back together and paid for the tune-up for which I was given a test sheet.
First I soon found the loss of power was just as before but the car the harder to start.
I went to a mechanic recommended by a work colleague for the brakes to be inspected and rectified as required. He was happy everything was perfectly serviceable for at least 10,000 miles except the one wheel cylinder which he replaced and while doing that changed the fluid. Then to the power loss and starting he found the carburettor wrongly set despite the test report I received.

I now use a local small garage for servicing and MOT and before that used another local garage for MOT. Both have always been fair.

Subsequently someone who used the same fast-fit centre for MOT three or four years from when their car was 4 years old and low mileage had a fail every year but once they swapped to the garage I now use for servicing and MOT they never had another fail.

Anyway back to tyres I have spoken to two tyre centres, one a MOT centre. Both said while they would recommend keeping with the OEM speed rating there was no issue with the V rated as above the manufacturers quoted maximum speed - remember if rather than the 16" OE alloys I had the 15" OE steel wheels the car would have left the factory with V rated tyres.
Also I now recall a couple of years ago another local tyre dealer who is a MOT test centre offered me V rated but then I could get W at a better price.

Now I can get the tyres I'm looking with a V rating at a very good price but W not available. My options for W are either various far east brands at a similar price or around £15 each more for a reputable brand.

[Chipped2]

My understanding with regard to the correct speed rating of the tyres fitted to each particular model has no bearing on a tyres maximum speed. I spoke to VW, Continental and others and the correct answer is the that the tyre must have the rating that it was tested with to gain TYPE APPROVAL when all the tyres parameters met the vehicles requirements with regard to weight, engine power and torque etc, etc.

I was told that to fit my 2002 Passat Sport Estate 130 TDi with V-rated 205 55x16 tyres would not meet Type Approval requirements and would fail its MOT. The car was Type approved with W-rated tyres.

If 15" wheels were fitted, (as they were as standard in Germany), V-rated tyres would be OK.

As there could be, would be..... Insurance claim issues when shod with the wrong tyres why take the risk. As others have stated the correct speed rating can be cheaper than the lower rating anyway...........!

[zollaf]

http://www.motuk.co.uk/manual_410.htm

as you can see here, speed ratings only apply to class 5 & 7 vehicles only, not tp class 4 ( cars). so you could put any speed rating tyre you like on whatever car you like and get a pass.

[Bratty]

Why not just dip into your glovebox and pull out your "European Certificate of Conformity" (which if you do not have should be available for a price! from the manufacturer of your vehicle).

That "EU C of C" states what wheels and tyres (speed ratings) that apply to your TYPE APPROVED vehicle.

If your vehicle is driving outwith the approved criteria then you must have supportive documentation.

Its not a MOT thing its "EU" Law (ie. Type Approval)

The vehicle should have been supplied with this document!

Dunk

[Bratty]

Worst case scenario!!?!!

I tip up for an MOT with an RS6 with over 500BHP, with tyres from a "garden wheelbarrow" stretched over the 20 inch rims!

Will it pass? (not theoretically, but actually!).

.

Dunk