Hankook Tyre Size Warning

Submitted: Monday, Feb 22, 2016 at 11:07
ThreadID: 131657 Views:2685 Replies:7 FollowUps:16
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Hi guys I believe we have found errors in tyre sizes in Hankooks current catalogue (2015/2016).

So if your buying tyres on diameter as I do you could potentially end up with an unroadworthy size on your car.

I found out when I recently wanted some genuine 32" AT tyres (816mm) , the dealer had a catalogue and in it it lists a 285/70/17 as exactly what I needed at 816mm and they were duly order and fitted.

Great tyres actually , I got Dynopro AT-M also known as RF10.

However soon after driving out of the shop on way to exploreOz coffee morning I felt something was wrong and speedo read incorrectly.

After quite some investigation I discovered the tyres were 831mm or 15mm larger than expected.

During my investigation I discovered that the Australian catalogue had size as 816mm but the American catalogue used the correct size as 831mm for identical tyres.


Most would know that that 285/70/17 is the equivalent tyre size to 285/75/16 and these are referred to as 33" tyres.
If you look at the image below from catalogue you will see 285/75/16 listed as 832mm and 285/70/17 as 816mm , whereas those 2 sizes are normally within a mm, so it looks like this error slipped past the editor of the catalogue.


A while back I discovered that Stanley flasks were specified wrong and Stanley were grateful and sent me a big container with a free sample of each of their products.

But its not looking so good with the tyres as the tyre dealer won't take them back and Hankook rep is currently off work so I thought I would let you know asap just in case your looking at the same thing.























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Reply By: Idler Chris - Monday, Feb 22, 2016 at 12:53

Monday, Feb 22, 2016 at 12:53
HI Robin,

I have just put on Federal's at 265/75R16 which are 804mm or 31.6".

I would check your compliance plate and if the tyres supplied are more than 50mm bigger, then the tyre fitter has broken the law. If this is the case threatening to report him should be enough to get a change over.
I believe the standard tyre for your vehicle is 275/65R17 which is 789mm. The tyre supplied at 831mm is 42mm bigger, so legal provided you have had no suspension lift. It is legal (in Vic) to raise your vehicle a max of 75mm with a combination of suspension lift and bigger tyres with no single element being greater than 50mm. So therefore provided you have not had a suspension lift of greater than 33mm (75 - 42) then you are still legal.
I understand that the authorities do not use manufactures specs to ascertain sizes but have a table which is probably the same as the ExplorOz chart.http://www.exploroz.com/Vehicle/Tyres/SizeCalc.aspx
If you have changed the suspension you may have to prove that it is not more than what is legal. If you are close to the legal limit I would be very friendly and courteous to anyone who should stop you, as if you get on the wrong side of them they could make life very difficult.
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Follow Up By: Robin Miller - Monday, Feb 22, 2016 at 14:25

Monday, Feb 22, 2016 at 14:25
Good stuff Chris, not worried about my >80mm lift , more worried about non Patrol owners who might get caught out.
As Patrol owners can rely on option 2 rules at least in Vic.

Under option 2 you can have tyres up to 15mm bigger , and key is that its not 15mm bigger than cars sticker , its 15mm bigger than anything fitted to that vehicle series.

Some patrols have come with 245/85/16 which is 822mm then you add the 15 so tyres can go up to 838mm provided the suspension itself isn't increased by more than 1/3rd up or down (34mm).

So I'm lucky there as I can be (789 to 838)=49mm + 34mm suspension = 83mm total.

Hope your Federals work out , what do you think of them ?

The Hankook I got are run around tyres as I've already got other bigger sets of wheels, and the kids think I'm crazy for wanting to return tyres cause there bigger than expected.

Even my wife says they look good , so I asked her if they look sexy - but got no answer yet !






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Reply By: Peter_n_Margaret - Monday, Feb 22, 2016 at 13:10

Monday, Feb 22, 2016 at 13:10
In terms of speedo accuracy, it is the rolling diameter which is important, not the inflated diameter.
That relationship will change slightly with profile differences, but not enough to make up that error :(

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Peter
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Follow Up By: Idler Chris - Monday, Feb 22, 2016 at 13:21

Monday, Feb 22, 2016 at 13:21
Hi Peter,
Am I missing something here? The rolling diameter is the circumference which is calculated by multiplying the diameter by pi. This is a fixed relationship so I do not understand your comment that profile differences will change the relationship.

Cheers,
Chris
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Follow Up By: Robin Miller - Monday, Feb 22, 2016 at 14:33

Monday, Feb 22, 2016 at 14:33
Hi Peter / Chris

The tyres usually have smaller rolling dia because of load differences and sometimes its hard to know just what specs the companies use - some include the number of revs / km but still do not say what the load is.

Its usually presumed that the load is max , but then most people run tyres at much less load normally , and even then the tyre dia grows as you go faster , these things are usually only 1 or 2 % though.

In my case , because I have GPS and speedo together I could tell instantly that the 2 speed readings differences were not what they should be !
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Follow Up By: Peter_n_Margaret - Monday, Feb 22, 2016 at 15:22

Monday, Feb 22, 2016 at 15:22
The rolling diameter is smaller than the inflated diameter (because of the 'flat'spot', and the flat spot will vary with profile), but should not vary with load if the pressures are adjusted appropriately for highway conditions.
In fact it is very complicated, and Michelin quote the following for the tyres that I use......

Free radius
Static laden radius
Rolling circumference
Revolutions per km.

And you can't use one to calculate the others. The dynamics are not simple.
May be useless information, but true?

Cheers,
Peter
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Follow Up By: Member - Boobook - Tuesday, Feb 23, 2016 at 19:06

Tuesday, Feb 23, 2016 at 19:06
Hang on a second. The diameter is the diameter is the diameter.
A tyre with a specific diameter will have a rolling circumference regardless of the profile.
circumference = pi x d.

What is an inflated diameter?. The diameter is specified by the manufacture and subject to wear, determines the rolling circumference surely.

I may be wrong but different diameters just don't make sense to me. A tyre with a specified diameter of 816mm will always have a rolling circumference of 2.563m. If it's at 60 PSI, 40 PSI 20 PSI or 19 PSI it makes no difference. 2.563m rolling diameter.
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Follow Up By: Robin Miller - Wednesday, Feb 24, 2016 at 10:32

Wednesday, Feb 24, 2016 at 10:32
Just a little explanation of how tyres rolling radius changes.

We did the research 3 or 4 years ago , i can't remember the post number so just using nominal figures in this reply.

When you drop tyre pressures a lot the height of axle above ground drops as tyre goes flatter.

This could make one think that the distance along the ground from 1 wheel revolution is shorter and hence maybe the oddmeter reads less , but this is essentialy not true, but it is in part true.

As others point out the circumference of the tyre does not change however what happens is that distortion and slippage of the tread occurs.

If the tyre was like a steel bulldozer track then no change to rolling circumference would occur.


Rough figures are - if tyre pressure is dropped such that radius reduced 5% then rolling circumference wills not drop by 5% but only by 1%


I have verified this with accurate tests, but again can't remember post number..








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Follow Up By: Member - Boobook - Wednesday, Feb 24, 2016 at 14:10

Wednesday, Feb 24, 2016 at 14:10
This video demonstrates it pretty well. Virtually no difference in rolling radius when significantly deflated except some slippage etc as Robin mentions. Like a bulldozer track.


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Reply By: swampy - Monday, Feb 22, 2016 at 15:33

Monday, Feb 22, 2016 at 15:33
hi
3% tire size tolerance, for speedo to still be accurate .Some also mention about the 50mm rule . There are legality issues with this subject and has varations state to state . Its a mine field .

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Follow Up By: Robin Miller - Monday, Feb 22, 2016 at 16:41

Monday, Feb 22, 2016 at 16:41
No worries Swampy , although what I am reffering to here is not those things about tyres but rather a product was described differently in a catalogue to what it actually is.
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Reply By: imatthew - Monday, Feb 22, 2016 at 16:15

Monday, Feb 22, 2016 at 16:15
There are a lot of misunderstandings about tyre sizes and what you can fit. It is because most people do not read past the headlines.

All states adhere to the national modification rules. If you comply with these rules, your vehicle will be legal in every state.

The national modification rules are known as VSB 14. The "LS" rules within this regulation deal with tyre sizes.

Everyone jumps to section 4.2 in these rules. This is the one that lists the 50mm increase, however, this rule applies when you are changing rims and tyres.

Section 4.1 deals with what tyre sizes you can fit if you keep the standard size rims. It states:

4.1 REPLACEMENT TYRES ON STANDARD (OR MANUFACTURER’S OPTIONAL) RIMS
Some tyre sizes have become obsolete and are no longer available. Equivalent replacement tyres with different size designations may be fitted without specific certification under this Section.
Every passenger car manufactured after 1972 (ADR 24) is fitted with a tyre placard that contains information on original and optional tyres and rims for that vehicle model.
A motor vehicle under 4.5 tonnes GVM which is required to comply with ADR 24 may be equipped with tyres other than those listed on the tyre placard provided that:
• • the load rating of the tyres is not less than the lowest load rating listed on the tyre placard of the vehicle or equivalent variant of that model vehicle;
• • the speed rating of the tyres fitted to a passenger vehicle is at least 180 km/h (S) when the tyre placard requires a higher speed rating than S;
• • the speed rating of the tyres fitted to vehicles with special features for off-road use of at least 140 km/h N when the tyre placard requires a higher speed rating than N; and
• • for all other vehicles a speed rating of at least 120 km/h.
• • In special circumstances, the speed rating may be less than the ratings specified above if the speed rating of the tyre is more than the vehicle’s maximum speed. This will need to be confirmed with the Registration Authority

I read this as you can fit any diameter tyre to the standard rims as long as they can be legally fitted to those rims. That is, tyres will have a rim size listed to what they can be fitted to. There is certainly no 50mm limit listed in these rules.

Now we can move on to section 4.2 if you are changing your rims. The biggest mistake people make is thinking that there is a specific diameter listed somewhere for each tyre size. This is not the case. You only have to look up the actual diameter of various tyres. Mud tyres tend to have a larger diameter for a specific size than say a road tyre, the diameters also vary between manufacturers. So what is the base diameter than I can go 50mm above.

ADR 23 deals with the requirements of tyres and their sizes. Up to 2009, there was only ever a minimum diameter specified for a given tyre size. So basically a given tyre size could have any diameter above a certain measurement. So if there is not requirement under the ADRs to have a certain diameter for a particular tyre size and the modification rules allow you to go 50mm above the diameter of the tyre size, it is very open ended about how large a tyre you can fit.

In 2009, ADR 23 actually brought in a range of diameters for a given tyre size. They came into line with the United Nations Regulations. These rules allow a minimum and maximum diameter for the size in question. Basically you calculate the theoretical diameter the same way as most of you do, that is, using the rim size, tyre width, and profile. The regulations state that for a 4WD tyre, the range in size can vary from 3% below the calculated diameter to 6% above.

So with a range of diameters that can easily range by 20 to 30mm, which diameter do you use in calculating how big you can go. I would suggest that you can use the maximum diameter as this is the diameter most closely related to mud tyres and if we are putting on bigger tyres, they are usually mud tyres.

But you can interpret these rules how you like. I am just highlighting that there is a little more behind the headline rules that everyone keeps on quoting
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Follow Up By: Robin Miller - Monday, Feb 22, 2016 at 16:35

Monday, Feb 22, 2016 at 16:35
Hi Matthew

Thats good info and one reason why you do see, and hence can optimize a given tyre size for your application.

Its not however the issue in this case , in this case the same product is given different descriptions in two different publications from the same company, subject to the same standards.
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Follow Up By: imatthew - Monday, Feb 22, 2016 at 16:44

Monday, Feb 22, 2016 at 16:44
Robin,

It is a matter whether the tyres are within the "standards". I would think that what you got was within the standards for that type of tyre of that size.

Then your only point for redress is whether they falsely advertised the tyres. If you got the diameter off a current official document from the company and they needed to be that diameter to fit the purpose you required them for, then they have to give you a refund under Australian consumer law. That is, the tyres were not fit for purpose. But the wrong diameter would have to be on a current official document provided by the person you purchased them from. If it is just off something that you found on the internet, I would not like your chances.
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Follow Up By: Robin Miller - Tuesday, Feb 23, 2016 at 08:03

Tuesday, Feb 23, 2016 at 08:03
No worries Matthew , fortunately the wrong figure is actually in the companies brochures.
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Reply By: imatthew - Monday, Feb 22, 2016 at 17:14

Monday, Feb 22, 2016 at 17:14
After rereading you figures, I am at a loss as to your issue. You quote a number of tyre sizes, but your calculated diameters appear wrong.
The calculated tyre size, using the profile, width and rim size, for a 285/70/17 is 831mm, exactly what you got. For a 285/75/16, the calculated diameter is 834mm, which is in line with the 285/70/17.
I thought the standard tyres on a Nissan were 265/75/16, which have a calculated diameter of 804mm.
I also doubt that you will find your new tyres are actually 831mm. As this is the default calculated diameter, it is rare that the actual diameter would line up with this. It could be up to 25mm bigger than this and still be within industry standards.
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Follow Up By: Robin Miller - Tuesday, Feb 23, 2016 at 09:19

Tuesday, Feb 23, 2016 at 09:19
No quite Matthew , I didn't go for a 285/70/17, I went a tyre that was a nominal 816mm as per company catalogue.

What was supplied was a nominal 831mm tyre, i.e. not what was advertised .

P.S. Since this post was put up the company has been contacted and recognized there error instantly.

Now the fun begins !
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Reply By: Life Member - Terry 80FTE - Monday, Feb 22, 2016 at 21:45

Monday, Feb 22, 2016 at 21:45
Gee's Robin, you wouldn't think such a "High Profile" company would make a blue like that.

I don't think anyone else would be looking to get hankooks anyway, would they? ;)


Cheers
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Follow Up By: Robin Miller - Tuesday, Feb 23, 2016 at 11:45

Tuesday, Feb 23, 2016 at 11:45
Its a much bigger operation than you might imagine Terry , and its very easy to see how the mistake was made.

In American catalogue they list 3 tyres as follows

265/75/17 (804mm)
275/70/17 (816mm)
285/70/17 (831mm)

So when it came to australia markets they reduced the product range by not stocking less used sizes like 275/70/17

So when you delete the 275/70/17 entry above the 285/70/17 moves up 1 click and lines up against the 816mm size entry.

Hence american catalogue is correct and aussie one gets wrong data.

After some detective work I have now spoken to local product manager.

He saw the issue instantly , and I suggested he send me a bunch of flowers as gratitude.

They haven't arrived yet.




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Follow Up By: D-MaxerWA - Tuesday, Feb 23, 2016 at 21:10

Tuesday, Feb 23, 2016 at 21:10
I have the very same tyres and love them. Speedo is more out now than before, but in the direction that means I wouldn't get a ticket. I now sit 9% over and not 5% over.

Most people missed Robin's point. The catalogue was wrong. I think he deserves a free set for pointing it out.

Those that went off on tangents.......... I will say no more.
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Follow Up By: Life Member - Terry 80FTE - Tuesday, Feb 23, 2016 at 21:29

Tuesday, Feb 23, 2016 at 21:29
I was meaning you get tyres 15mm too tall, because it's a "High Profile" company,,, oh! doesn't matter.

The problem is still theirs, so tell them to import some 275/70x17 tyres, (They only have to put them in the next container) or give you back the money.
Unless you really do desire bigger wheels, then no worries.

Cheers
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Reply By: pop2jocem - Monday, Feb 22, 2016 at 22:36

Monday, Feb 22, 2016 at 22:36
A lot of Landcruisers, Nissan Patrols, and probably a heap of other 4WDs and 2WDs, mainly the workhorse versions, have come with a tyre that was quoted as being a 7.50x16 in the old imperial sizing. Personally I don't remember the numbers on the sidewalls ever stating a profile percentage.
Does anyone know what a 7.50x 16 tyre in 6 or 8 ply have as a percentage ratio? Probably some variations between manufacturers, but I would have thought most of the standard offerings would be pretty close to maybe 75 or 85%.
I think most of them went 31" or 32" diameter.

Actually after a bit more "Googling" one source seems to be of the opinion that the "average" 7.50x16 were usually 100% aspect ratio i.e. the tread width and the sidewall height were the same.

Cheers
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Follow Up By: imatthew - Monday, Feb 22, 2016 at 23:21

Monday, Feb 22, 2016 at 23:21
In the imperial they are 100% as you state. In the metric, like 205R16, they are either a 80% or 82% ratio.
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