Page 1 of 2 1 2 LastLast
Results 1 to 20 of 24
  1. #1
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Tyres and Speed rating

    So being new to the forum I thought Id like to maybe talk about tyres which is a topic very much discussed but I havn't seen much talk about tyre speed ratings.

    So the time has come for me to replace tyres on my Fortuner so being a technical person I started my research and ifo gathering before taking the plunge. During this time I looked at many brands from BFG to Dunlop AT3G. I began to look at the speed ratings on these tyres and started taking that into consideration.
    Now I do understand as a 4x4 driver these vehicles are not high speed vehicles but yes these new bakkies are very capable of travelling at a significant speed. (The law is and speed limit is something else)

    My concern drew closer as these AT tyres are designed for a variety of conditions but as some of these tyres really would be a risk at high speeds on the black top.

    Example is the Dunlop AT3G 265/65/17 are only speeed rated to a speed of 170km/h which I strongly believe is less once laden, starts to wear as well as varied tyre pressures but the 18inch is rated to 180km/h. Now even though these speeds are high it brings me to question the following when purchasing tyres:

    1. How do I drive
    2. What is the purpose of my vehicle and tyre
    3. What am I looking to get from this tyre
    4. Would I feel safe having a lower speed rated tyre
    5. Will you be confident to push your vehicle and tyre should the need arise

    Taking all the above into consideration I settled on ordering the Hankook dynapro ATM RF10. The fortuner is mostly highway use with occasional off road use.
    My fortuner has been remapped and this was also a deciding factor.

  2. #2
    Join Date
    Oct 2011
    Location
    krugersdorp
    Age
    47
    Posts
    1,585
    Thanked: 568

    Default Re: Tyres and Speed rating

    "OVERBOOST"(forum name)
    "only speed rated to a speed of 170km/h"
    "fortuner has been remapped"

    are you in a hurry?

  3. The Following 4 Users Say Thank You to jadranko For This Useful Post:


  4. #3
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    Quote Originally Posted by jadranko View Post
    "OVERBOOST"(forum name)
    "only speed rated to a speed of 170km/h"
    "fortuner has been remapped"

    are you in a hurry?
    Well I do performance tuning to bakkies as hobby so hence the name.
    Speed rated is because I have started to see an increase in bakkies being raced (I dont race bakkies, thats not what they are for)
    Well I enjoy the increase in torque and overall power when needed and especially when loaded or pulling a trailer.

    No as much as others race bakkies, highway or whatever else alot of these owners are either goin through tyres faster so fitting tyres they get a better deal on or those that spend dont understand that 4x4s are purpose built. I seen a range sport rover with Goodyear duratrac tyres fitted as a daily that never goes on gravel. Thats why its concerning as SUVs and 4x4s have become more common on our roads the tyres they fit can pose a great risk to their safety as well as others.

  5. #4
    Join Date
    Apr 2018
    Location
    JHB
    Posts
    363
    Thanked: 325

    Default Re: Tyres and Speed rating

    My BFG's are rated to 170kph. On my Defender that's just a little too ambitious... not even downhill with a gale force wind
    Last edited by Sheldon93; 2021/09/16 at 09:27 AM.
    2018 Suzuki Jimny - Expedition vehicle
    2002 Land Rover Defender - Daily Drive

  6. The Following 2 Users Say Thank You to Sheldon93 For This Useful Post:


  7. #5
    Join Date
    Oct 2017
    Location
    Rustenburg
    Age
    52
    Posts
    4,807
    Thanked: 8801

    Default Re: Tyres and Speed rating

    A tireís speed rating indicates the optimal speed that the tire can safely maintain over time. In short, itís the fastest speed a tire can handle before it no longer performs as designed. The higher the speed rating, the better control and handling youíll have at higher speeds.
    The speed rating system was developed to help control the safe performance of tires at standardized speeds. A tireís certified speed rating is given a letter from A to Z, ranging from 5km/h (3mph) to above 300 km/h (186 mph).
    This rating system (see below) shows the top speed for which a tire is certified. It does not indicate the total performance capability of a tire.
    If you are worried about a tyre's speed rating only being 180/170km/h on a Fortuner that is factory governed to an indicated 180km/h then.. I cannot comment.

    If you need a higher rating than that.. you should not be in a 4x4 unless like your "Ranger Sport Rover" that you mention, you use it for posing on tar.

    The tyres I use are for the purpose I choose, and that is being durable off road, and comfortable on road.
    _______________________________________
    Andrew van Staden
    FJ - 2 Batteries, a tow bar, OME, Adventurers, and a drawer
    Ex:
    Ranger 3.2, LC 76 V8, Navara 2.5, NP300, Patrol 4.8, Everest 3.0, Jimny 1.3, Defender 110 SW Puma

  8. The Following User Says Thank You to Hedgehog For This Useful Post:


  9. #6
    Join Date
    Jul 2017
    Location
    Paulshof
    Age
    36
    Posts
    290
    Thanked: 423

    Default Re: Tyres and Speed rating

    GY Wranglers are rated to 210Km/h, good enough for me as the Amarok seems to hit a wall just below there.
    2018 VW Amarok V6 Auto 4Motion

  10. The Following User Says Thank You to Ooba For This Useful Post:


  11. #7
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    [QUOTE=Hedgehog;4733336]If you are worried about a tyre's speed rating only being 180/170km/h on a Fortuner that is factory governed to an indicated 180km/h then.. I cannot comment.

    If you need a higher rating than that.. you should not be in a 4x4 unless like your "Ranger Sport Rover" that you mention, you use it for posing on tar.

    The tyres I use are for the purpose I choose, and that is being durable off road, and comfortable on road.[/QUOTEI ]

    I personally do not need a tyre rated higher but when I have remapped a few of these new bakkies that can easily run the clock but the owner wants the vehicle fitted with an AT tyre that will definitely not handle those speeds but looks good. For example a hilux fitted with BFG can cruise comfortably at 160km/h on the highway but that is already close onto tyres limit. I did mention that i dont believe bakkies or 4x4s are ment to raced or for high speed but its happening

  12. #8
    Join Date
    Jan 2012
    Location
    King Williams Town
    Age
    53
    Posts
    8,407
    Thanked: 2306

    Default Re: Tyres and Speed rating

    Sit at law abiding road speeds as indicated by those round pretty signs on the road edges, then you won't worry what speed rating tyres are made to.
    Isuzu STD 2.5d 2x4 rear diffy lock
    2x spotlight,2x fog lights
    215/80/R15c tyres
    1 x great humourous driver
    GPS,Bluetooth
    Eagle eye dash cam --stolen ..bought another one
    snorkel soon
    Craig
    I DON'T LIVE IN AFRICA,AFRICA LIVES IN ME- Kyle my son

  13. The Following 3 Users Say Thank You to hunter26 For This Useful Post:


  14. #9
    Join Date
    Jul 2011
    Location
    127.0.0.1
    Age
    38
    Posts
    1,029
    Thanked: 1435

    Default Re: Tyres and Speed rating

    Quote Originally Posted by OVERBOOST View Post
    Quote Originally Posted by Hedgehog View Post
    If you are worried about a tyre's speed rating only being 180/170km/h on a Fortuner that is factory governed to an indicated 180km/h then.. I cannot comment.

    If you need a higher rating than that.. you should not be in a 4x4 unless like your "Ranger Sport Rover" that you mention, you use it for posing on tar.

    The tyres I use are for the purpose I choose, and that is being durable off road, and comfortable on road.
    I personally do not need a tyre rated higher but when I have remapped a few of these new bakkies that can easily run the clock but the owner wants the vehicle fitted with an AT tyre that will definitely not handle those speeds but looks good. For example a hilux fitted with BFG can cruise comfortably at 160km/h on the highway but that is already close onto tyres limit. I did mention that i dont believe bakkies or 4x4s are ment to raced or for high speed but its happening
    I'm not sure why this thread exists.

    AT tires speed rating will be lower, because they are not made for speed. They are made for grip in the rough and durability. 170km/h is 50km/h over the fastest allowed speed in SA, so "technically" they are made well above what is allowed by law.

    If you are into drag racing, you won't be fitting tires not made for it.

  15. The Following User Says Thank You to IcePick88 For This Useful Post:


  16. #10
    Join Date
    Oct 2011
    Location
    Midrand
    Age
    49
    Posts
    3,719
    Thanked: 2497

    Default Re: Tyres and Speed rating

    Quote Originally Posted by hunter26 View Post
    Sit at law abiding road speeds as indicated by those round pretty signs on the road edges, then you won't worry what speed rating tyres are made to.
    I believe it can be used to repudiate a claim if your tyres are rated lower than the Vmax of the vehicle they are fitted to, so it may be somewhat relevant?

    With the price of fuel these days I am more interested in consumption than speed, so I am happy not to exceed 120 and generally potter along at 100-110. But would be interested to hear from the brokers their view?

  17. The Following User Says Thank You to stephenplumb For This Useful Post:


  18. #11
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    Quote Originally Posted by IcePick88 View Post
    I'm not sure why this thread exists.

    AT tires speed rating will be lower, because they are not made for speed. They are made for grip in the rough and durability. 170km/h is 50km/h over the fastest allowed speed in SA, so "technically" they are made well above what is allowed by law.

    If you are into drag racing, you won't be fitting tires not made for it.
    Im not denying the law. But looking at tyre vs a vehicles ability to get close to or pass the tyres limit. Performance cars are still restricted to follow the legal speed limit but this doesnt mean that they are cannot exceed the legal road speeds hence they come fitted with high rated tyres. bakkies come fitted with more road pattern tyres from factory as the manufaturer tests the vehicles performance and needs a tyre to match that.

  19. #12
    Join Date
    Jun 2012
    Location
    Benoni
    Age
    46
    Posts
    1,571
    Thanked: 3820

    Default Re: Tyres and Speed rating

    Quote Originally Posted by stephenplumb View Post
    I believe it can be used to repudiate a claim if your tyres are rated lower than the Vmax of the vehicle they are fitted to, so it may be somewhat relevant?

    With the price of fuel these days I am more interested in consumption than speed, so I am happy not to exceed 120 and generally potter along at 100-110. But would be interested to hear from the brokers their view?
    This, by law you must fit the same (or higher) speed rated tyres than OEM supplied the car with. If your insurer wants to get sticky they can repudiate the claim regardless of the speed involved in the accident.

    I think we have quite a few people on this forum driving around with potentially uninsured vehicles due to this
    Last edited by mullerza; 2021/09/16 at 10:50 AM.
    Anton Muller

    "That which can be asserted without evidence, can be dismissed without evidence." Christopher Hitchens.

    2020 X3 M40i
    Birkin SR20VET race car

  20. The Following 2 Users Say Thank You to mullerza For This Useful Post:


  21. #13
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    Quote Originally Posted by stephenplumb View Post
    I believe it can be used to repudiate a claim if your tyres are rated lower than the Vmax of the vehicle they are fitted to, so it may be somewhat relevant??
    Exaclty the type of discussion that Im interested in.

  22. The Following User Says Thank You to OVERBOOST For This Useful Post:


  23. #14
    Join Date
    Oct 2011
    Location
    Midrand
    Age
    49
    Posts
    3,719
    Thanked: 2497

    Default Re: Tyres and Speed rating

    Whats really interesting is how much tech goes into making tyre. Everything in engineering is a compromise. In the old days your crossply Ser1 could probably do no more than 80km/hr.

    Now you have SUV pushing well north of 2.5tons, capable of north of 200km/hr and you still want to be able to mash up a sani pass, or similar? It really does push the poor old tyre engineer quite hard to meet all requirements.

    Having said that I spoke to a tyre engineer at Dunlop and he said one of the worst things you can do to a tyre is drive with low inflation, in hot sand, while towing a heavy boat! Eeek! This puts a huge amount of thermal load into a tyre. At one point they were having problems with Prados that were coming in as full imports with Dunlops fitted. He was on about bandages and belts and things, and said that the stock tyres were no good for SA conditions.

  24. #15
    Join Date
    Oct 2011
    Location
    krugersdorp
    Age
    47
    Posts
    1,585
    Thanked: 568

    Default Re: Tyres and Speed rating

    Quote Originally Posted by mullerza View Post
    This, by law you must fit the same (or higher) speed rated tyres than OEM supplied the car with. If your insurer wants to get sticky they can repudiate the claim regardless of the speed involved in the accident.

    I think we have quite a few people on this forum driving around with potentially uninsured vehicles due to this

    all tires today can go way above legal speed limit but most of accidents happen below that.
    it is easy to determine speed involved in accident,and to repudiate will not go so easy with ombudsman if one prove that legal limit(road and tire) was not exceeded.

    my look on this is as if insurance repudiate claim because of mushroom plug
    as i bought a car without one.

  25. #16
    Join Date
    Nov 2007
    Location
    Pennington
    Age
    59
    Posts
    728
    Thanked: 197

    Default Re: Tyres and Speed rating

    My vehicle was fitted with Wranglers from the factory. They are good for 210km/h. My vehicle has a 2.5inch suspension lift and is fitted with m/t tyres that are good for 160km/h. The veh is insured to be covered when traveling off road and the mods are specified on my insurance. Cover is 100%

  26. #17
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    Quote Originally Posted by mplester View Post
    My vehicle was fitted with Wranglers from the factory. They are good for 210km/h. My vehicle has a 2.5inch suspension lift and is fitted with m/t tyres that are good for 160km/h. The veh is insured to be covered when traveling off road and the mods are specified on my insurance. Cover is 100%
    Interested to find if they can have an issue with M/T being used on tar as they are more specific to being used off road than on tar.

  27. #18
    Join Date
    Nov 2010
    Location
    Henties
    Posts
    4,338
    Thanked: 2185

    Default Re: Tyres and Speed rating

    Quote Originally Posted by OVERBOOST View Post
    Example is the Dunlop AT3G 265/65/17 are only speeed rated to a speed of 170km/h which I strongly believe is less once laden, starts to wear as well as varied tyre pressures but the 18inch is rated to 180km/h.

    Taking all the above into consideration I settled on ordering the Hankook dynapro ATM RF10. The fortuner is mostly highway use with occasional off road use.
    My fortuner has been remapped and this was also a deciding factor.
    Sorry, but if your concerns are genuine, I don't understand your decision making.
    With the Dunlop AT3G you would have had a LT spec tyre with a load rating of 1400 kg, speed rating of 170 km/h.
    You decided to go instead with a 4 ply rated (referring to the tread surface!!!) tyre with a much lesser load rating of 1120 kg but a higher speed rating of 190 km/h. Yet these 4 ply rated Hankooks are known to give trouble on gravel roads quite easily.

    According to your statement, you don't race the Fortuner, hence you don't make use of the higher speed rating. Yet you do use it off road occasionally. Wouldn't the higher load rating be of more benefit to you, giving you more safety margin, than a higher speed rating, which is anyway 50+ km/h above the legal limit?

    What does the fact that your Fortuner has been remapped (yet another one of those ) have to do with your decision to go with an overall inferior tyre with a higher speed rating, unless you do exceed the legal speed significantly and regularly?

    With regards to insurance: if you are with a decent insurance company, ask them what their take is on the speed rating issue. I have never had a problem getting a vehicle through roadworthiness with tyres which had a lower speed rating than the vehicle's top speed.
    My insurance advised me, that as long as I drive within the given speed rating of the tyre, there will not be a problem.

    I'm not sure whether this insurance claim story isn't just that, another story. After all, people on this forum are still floating the rumor that if you drive a tyre older than 5 years your insurance might not pay out in case of an accident. This has been proven wrong numerous times, but the rumor comes up regularly.

    Most AT tyres are rated for 190 km/h anyway and have a better reputation with regards to punctures than the one you have chosen.
    Last edited by HugoNotte; 2021/09/16 at 12:26 PM.
    2012 FJ Cruiser
    1983 FJ60 Landcruiser -sold-

  28. #19
    Join Date
    Sep 2021
    Location
    KZN South Coast
    Posts
    25
    Thanked: 10

    Default Re: Tyres and Speed rating

    Quote Originally Posted by HugoNotte View Post
    Sorry, but if your concerns are genuine, I don't understand your decision making.
    With the Dunlop AT3G you would have had a LT spec tyre with a load rating of 1400 kg, speed rating of 170 km/h.
    You decided to go instead with a 4 ply rated (referring to the tread surface!!!) tyre with a much lesser load rating of 1120 kg but a higher speed rating of 190 km/h. Yet these 4 ply rated Hankooks are known to give trouble on gravel roads quite easily.

    According to your statement, you don't race the Fortuner, hence you don't make use of the higher speed rating. Yet you do use it off road occasionally. Wouldn't the higher load rating be of more benefit to you, giving you more safety margin, than a higher speed rating, which is anyway 50+ km/h above the legal limit?

    What does the fact that your Fortuner has been remapped (yet another one of those ) have to do with your decision to go with an overall inferior tyre with a higher speed rating, unless you do exceed the legal speed significantly and regularly?

    With regards to insurance: if you are with a decent insurance company, ask them what their take is on the speed rating issue. I have never had a problem getting a vehicle through roadworthiness with tyres which had a lower speed rating than the vehicle's top speed.
    My insurance advised me, that as long as I drive within the given speed rating of the tyre, there will not be a problem.

    I'm not sure whether this insurance claim story isn't just that, another story. After all, people on this forum are still floating the rumor that if you drive a tyre older than 5 years your insurance might not pay out in case of an accident. This has been proven wrong numerous times, but the rumor comes up regularly.

    Most AT tyres are rated for 190 km/h anyway and have a better reputation with regards to punctures than the one you have chosen.
    Yes I do not make use of the speed rating but from past personal experience a tyre with a lower speed rating being driven below the speed limit does not handle as well in poor weather conditons. I have had hankooks on previous vehicles and driven alot more gravel without ever having any issues or punctures so I decided on going with tried and tested rather than something I am unsure about or wouldnt be confident in.
    Having the vehicle remapped has helped be reduce my fuel consumption by 1.5L/100km as well as allowed me to reach a higher speed when I was forced to during an emergency situation.
    My Hilux is fitted with Michellin Ltx but I feel its more partial to road than as an A/T tyre. I have tried Bridgetone dueler d697, contis, yokohama, BFG, Goodyear as well as Dunlop tyres over the years but as most pleased with hankook overall. (personal experience)

  29. #20
    Join Date
    Jul 2020
    Location
    Roodepoort
    Age
    61
    Posts
    180
    Thanked: 314

    Default Re: Tyres and Speed rating

    This discussion has now got my mind going: if a tyre is rated for a certain speed, how is that rating affected by load. For example, will a tyre rated for 180km/h on an unloaded Hilux will become unsafe at a lower speed if there is a 500 kg load at the back?

    Also, what is the safe loading limit of an AT tyre? Is that specified in any way?
    Johan Swanepoel

    "Nkabe ke ngwana wa morago"

Page 1 of 2 1 2 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •