disco-dad Posted March 17, 2011 Share Posted March 17, 2011 hi everyone.just wondering what the legalities are of running offroad tyres on the road.tyres in question are fedimma sirrooco's.the speed rating for these is J or 62 mph.any input welcomed. p.s tyres are 31x10.5x15 on mods.fitted to a modified disco with 2" lift Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 17, 2011 Share Posted March 17, 2011 Well TECHNICALLY, under Construction & Use a Tyre must be of a speed rating to suit the car / 4x4 from the manufactuer with a tyre that suited the vehicle on exit from factory - so whatever it had as std is the minimum rating. So, a V8 90 had a top speed of I think 88, so a Q speed of 99 is ok but a L speed rating of 62 is not I say technically as I know of most mates who drive with underrated speed rated tyres, esp simex ETs etc, but it there in the legal small print. MORE worrying (to me) is the meaning of the speed rating, again my understanding is that a speed rating means that the tyre has passed at the approved speed + 10 MPH on top for something like 20 mins without falling apart Er - Kin hell So, hence my concern that with the up and coming near 400 BHP 5.2 JED V8 I have tyres that actauly uit my speeds, and I do regularly do more than 62 MPH NOW - so I need a tyre that doesn't have a low speed rating for legal and peace of mind reasosn It is one of the "Pub Arguements" on speed ratings, and I know of no cases where someone has come a cropper, but, it won't be me Nige Quote Link to comment Share on other sites More sharing options...
disco-dad Posted March 17, 2011 Author Share Posted March 17, 2011 cheers nige.i'm thinking of changing them for something bigger anyway,33's or maybe even 35"s.just cant make up my mind which brand to go for.i mainly go to pay and play days with my son (ricky tango) but he thinks that i should go for something with an aggresive tread pattern only running standard diffs,no lockers etc. most of the aggresive ones have a low speed rating,so i'm not sure whether bfg km2's for eg would pull me through the mud as well as say insa turbo's it's ok for him with all of the gadgets in the axles Martin Quote Link to comment Share on other sites More sharing options...
Dave W Posted March 17, 2011 Share Posted March 17, 2011 The legal requirement is that the tyres fitted are suitable for the use they are being put to. Providing you don't exceed the rating of the tyres you're fine. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 17, 2011 Share Posted March 17, 2011 The legal requirement is that the tyres fitted are suitable for the use they are being put to. Providing you don't exceed the rating of the tyres you're fine. I fink Dave just might be right and I may be wrong... Found this Tyre speed ratings explained: This online guide serves as a reference for our visitors and customers Please feel free to give us a call at 0845 094 09 09 if you would like to inquire about our extremely competitive prices for car tyres delivered free throughout mainland UK. You will find your speed rating on the side of your tyre at the end of a series of numbers - as shown in the picture in the left V is the speed symbol. For MOT requirements in this country, it is not necessary to fit a tyre with a speed rating to match the original vehicle fitment or the maximum speed of the vehicle. Tyres must be suitable for the purpose for which the vehicle will be used. Insurance companies might say that a vehicle should be fitted with the tyres having the speed rating recommended by the car manufacturer: but even if you fit Z-rated tyres for speeds over 150 mph they will not insure you if you drive in excess of 70 mph in this country! Never the less the vehicle manufacturer has to recommend a tyre with a rating to match the maximum speed of the car because when it leaves the factory he does not know exactly where the car is going or for what purpose it might be used. You might want to use the car in a country where higher speed limits apply than the UK or take it to a race track at the weekend The tyre speed rating (i.e. S) is the maximum speed for which the tyre is rated. For example, the S rating identifies speeds up to 112 mph table below shows rating catagories. - Speed symbol Miles/ Hour Kilo/Hour N 87 140 P 93 150 Q 99 160 R 106 170 S 112 180 T 118 190 U 124 200 H 130 210 V 149 240 Z 150+ 240+ W 168 270 Y 186 300 And this : http://www.tyrerescue.co.uk/law.htm from Manchestser police Nige PS Dave - I think I love you as this opens a few better doors for me tyre wise (Darling) Nige Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted March 18, 2011 Share Posted March 18, 2011 Well you learn something new every day. I too thought you had to fit tyres appropriate to the "original equipement" state of the vehicle ie as good or better than originally fitted. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted March 18, 2011 Share Posted March 18, 2011 And this : http://www.tyrerescue.co.uk/law.htm from Manchestser police WRT the above - a couple of points if I may: 1. It is my understanding that the first line on the link: "Did you know that you are not insured when driving on illegal tyres? " is incorrect. On a radio prog a while ago a spokesman said that basic third-party cover would always apply even if the vehicle and or driving is illegal. Now I know that statement is no better than "My mate said", but that leads me on to point 2: 2. In spite of having the Greater Manchester Police logo on there, the web-site is commercial and is selling tyres. Finally - I firmly believe what Dave said is correct, however I would hate to have to stand up and have somebody ask me: "were you aware that the Range Rover official driver's manual states that "Fuel injected vehicles must be fitted with 'S' rated tyres"? Even though I believe I am legal if I stay within the rated limits, I hope I never have to test that in court! Quote Link to comment Share on other sites More sharing options...
zardos Posted March 18, 2011 Share Posted March 18, 2011 Remember a lot of vehicle manufacturers now supply their vehicles with space saver spare tyres which have a lot lower speed rating. So if they are happy legally doing this knowing that all they have done is provide a warning not to exceed the tyre's speed, then it should be OK to run lower speed tyres as long as you don't actually exceed the speed rating. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 18, 2011 Share Posted March 18, 2011 Plus, as mentioned recently on here, winter tyres are rarely rated as high as summer tyres, which we all use 99% of the time. Quote Link to comment Share on other sites More sharing options...
nicks90 Posted March 18, 2011 Share Posted March 18, 2011 just to add to the mix - speed ratings are not just about the overal speed the tyre can withstand, its also about the power the tyres can handle during acceleration, you're average BMW M5 might manage 155mph. But theoretically it could drive about on tyres speed rated for 70mph in this country. BUT would those tyres cope with 400+bhp screaming through them during fast acceleration from the lights without being torn to bits? Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted March 18, 2011 Share Posted March 18, 2011 <br>Remember a lot of vehicle manufacturers now supply their vehicles with space saver spare tyres which have a lot lower speed rating.<br>So if they are happy legally doing this knowing that all they have done is provide a warning not to exceed the tyre's speed, then it should be OK to run lower speed tyres as long as you don't actually exceed the speed rating.<br><br><br>Excellent point! I will remember that argument Quote Link to comment Share on other sites More sharing options...
Escape Posted March 19, 2011 Share Posted March 19, 2011 MORE worrying (to me) is the meaning of the speed rating, again my understanding is that a speed rating means that the tyre has passed at the approved speed + 10 MPH on top for something like 20 mins without falling apart As I understand it, the speed rating is performed at maximum tyre load, so this should give us 'normal' users some piece of mind. For heavy transport equipment, max load is usually given for different speeds, (partly) due to the performance of the tyres. For some more confusion, in Belgium you need tyres rated to the maximum speed of the car with the speed rating mentioned on the MOT form. But only for passenger cars... And for some commercial vehicles (onde Defender might have them listed, another identical one might not)... And they don't always check it. In winter, you're allowed to run winter tyres with as low a speed rating as you like, as long as you put a warning sticker on the dash. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted March 22, 2011 Share Posted March 22, 2011 Remember a lot of vehicle manufacturers now supply their vehicles with space saver spare tyres which have a lot lower speed rating. So if they are happy legally doing this knowing that all they have done is provide a warning not to exceed the tyre's speed, then it should be OK to run lower speed tyres as long as you don't actually exceed the speed rating. They get around it because it says both in the owner's manula and on the rim that there is a max speed of 50mph. I might have read somewhere that this is a legal maximum irrespective of what the manufacturer says, but I may have dreamed it. IIRC the new RR has a clause in the manual for AT/MT tyres rated below the original eqipment spec, stating that maximium speed the vehicle can be driven on those tyres. As said by others non of us shoud be driving at above 70mph anyway, should we? Quote Link to comment Share on other sites More sharing options...
TDi.Si Posted March 24, 2011 Share Posted March 24, 2011 I thourght it was illegal to have different sized tyres fitted on the same axle? Thus making space savers illegal, unless you fit 2! Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted March 26, 2011 Share Posted March 26, 2011 You're right it is, under normal circumstances. Space savers have to be tested during homologation and the speed of the car should be limited during their use. They aren't the smartest idea I've ever come across but it's abbout saving weight on something most people never use. Quote Link to comment Share on other sites More sharing options...
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