Tyre speed rating question. How low can you go?

[dhutch]

Hi, quick question about speed ratings for a mate.

He has a series landrover and is looking at geting some new, ex-army, tyres for it (Michelin XZY 7.50 R16 's) but they appear to be all 65mph speed rating.

I doesnt ever intend to go over 65 on them, however if you push her, flatout she she will do about 70 maybe 75.
- So he's conserned about the legality of fitting varous rating tyres, interms of MOTs and Insurence and that.

I was going to post this in 'offroad' but i guess it applys to all cars really.


Daniel

[dhutch]

No replys at all?

I would have thought someone would know maybe?

Clearly in many ways i would make sence to make a legal requirment to have the speed rating exceed the manufactors quiteed top speed maybe.

However the tyres on our trailer are ok rated at 70mph, and while you would be fair stupid to be towing any faster than that. The car its behind is/couldbe capable of well over that.

[Orangecurry]

I think the MOT can be failed if the load index is too low, and IIRC there is a speed-rating table the MOT station could look up for a car; I'm sure they rarely bother, and would the LR be in such a table?

At the end of the day, it'll be down to the MOTer, and that's a most subjective thing.

[JR]

Could be OK. The tyres have to be suitable for the vehicle and the use to which they are being put.

[Kermit power]

Bear in mind though that the maximum speed rating gives an indication of the general suitability of the tyre for the car, not just the top speed it can run at.

My ZT has a maximum speed of 155mph. Even on track days with long straights, I'm very unlikely to ever exceed 115-120mph in it, but I wouldn't drop below manufacturer's specs on the load rating because I also need the tyre to hold up under robust cornering at slower speeds and the like.

What is the recommended fit for a Series Landie?

[GasMonkey]

kwikfit.co.uk said:

Although not illegal, it is not recommended to have tyres with a lower speed rating or load capacity than the manufacturer recommended tyre specification for your vehicle, or to have a combination of different tyre construction types.

Max speed rating MPH
Q 99
R 106
S 112
T 118
H 131
V 149
VR 131
W 168
Y 186
ZR 149

Tyres are rated by speed and weight carrying ability, site suggests 85Q for a LR 90
(515kg x 4) (99mph)

kwikfit site

HTH

Edited by GasMonkey on Sunday 3rd February 23:16

[Andy Sargeant]

"Q" rating on tyres does mean 99mph max, Gasmonkey is quite right, mind you a series landie getting to 99 would be intresting.
If we can help out with tyre questions try us as we are into 4x4 and HI-performance tyres.
www.ajstyres.co.uk

[900T-R]

VR is the same as V - 149 mph/240 km/h. ZR used to be the catch-all for '149 mph/240 kmh+' before the W and Y categories came in.

[JR]

900T-R said:

ZR used to be the catch-all for '149 mph/240 kmh+' before the W and Y categories came in.

ZR has not changed. W and Y are sub divisions of Z.

[900T-R]

JR said:

900T-R said:

ZR used to be the catch-all for '149 mph/240 kmh+' before the W and Y categories came in.

ZR has not changed. W and Y are sub divisions of Z.

Correct, it's still part of the international standard for speed indexes (I got ZR fronts for the Chimaera last year) - however I don't think I've seen any new tyre designs/applications that are desginated ZR instead of W and Y for some time now...

[JR]

900T-R said:

I don't think I've seen any new tyre designs/applications that are desginated ZR instead of W and Y for some time now...

A few here: http://www.pirelli.co.uk/web/catalog/car-suv-van/c...
although they are quite extreme. I hadn't noticed that there were so few Z rated tyres now.

[tazbabe]

might be something in here that could help you answer the question@

http://www.carbibles.com/tyre_bible_pg2.html

[Rob_the_Sparky]

This: http://www.tyresave.co.uk/tyreinfo.html says that the MOT should not fail you for having tyres lower than the car's max speed rating as long as they are fit for purpose. May be debateable if you are talking about tyres that are not rated for UK speed limit though.

Does also point out that the insurance company may also have something to say about the speed rating so worht talking to them as well...

Rob

P.S. Looking at the same problem from a different angle and found your thread via a search...

Edited by Rob_the_Sparky on Friday 8th May 13:15

[JR]

Rob_the_Sparky said:

P.S. Looking at the same problem from a different angle and found your thread via a search...

Care to elaborate?

[dhutch]

Just as follow up, my mate bought the tyres, fitted them, and has been through an MOT with them without any issues.


Daniel

[normalbloke]

Blimey, I have G rated on mine!!