Tyres in general but RV in particular

moandick

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Jul 28, 2007
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I have always worked under the following credo:

As far as I am aware the way to tell the age of a tyre is by the date stamp on the tyre wall.

This should look something like...........

489 which equates to the 48th week of 1999

and this style should have stopped in 2000 to be replace by:

0305 which equates to the 3rd week of 2005.

Bearing in mind I have been advised that tyres should be changed every 5 years irrespective of condition -

it would seem that any tyre which does not have a '0' (zero) before the last digit should definitely be considered 'dodgy'

and any tyre which has a '0', '1' or '2' as the last but one digit should be considered for change pretty soon.

Can anybody (who really knows the subject) tell me if I'm right or wrong or tell me any better way, please?
 

American Dream

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Aug 20, 2007
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Hi MO and Dick,

Sharon (RockieRV) posted a thread in November on this.

The link to the data from Tyresafe is HERE.

Hope the information is helpful.
 
Last edited:
Jul 29, 2007
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Hi dick I believe Kands had a tyre on his previous RV that was 14years old, not sure how he had it checked but he said it was ok.

Tyre manufactures have two problems when advising dates, the possiblity of being sued, so they err very much on the safe side, and they want your money. ::bigsmile:

Olley
 

American Dream

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I guess the main criteria are that:-
the tyre has been inflated correctly throughout it's life so far
the sidewalls aren't showing signs of cracking
and the integrity if the tyre is intact with no cuts or splits!

The amount of shredded and delaminated tyres seen on motorways bears evidence to this.

I have only had one go and that was down to the fact it was an inner rear that I had inadvertantly slightly OVER inflated after taking the previous owners advice on pressures.:Doh:
 

johnsandywhite

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I have only had one go and that was down to the fact it was an inner rear that I had inadvertantly slightly OVER inflated after taking the previous owners advice on pressures.:Doh:
:Sad: I had the opposite on our old Coachmen. They advised 60/65 (too low). Had a double blow-out on the offside (passenger) rear. Had a blow-out on the Newmar offside (passenger) front due to it having locked up when evading a stupid truck driver in New Orleans. :RollEyes:

I believe that age plays a small part in the wear and tear of tyres. Weather and driving conditions have more effect. IMH&HO.
 
OP
moandick

moandick

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Thanks for those replies, MHFunsters - they are most helpful - especially Sharon's link to an article BUT what I am really looking for is the proper and correct manner of reading the tyre date.

From Sharon's article I have just emailed the British Tyre Manufacturers Association to see if any of them will enlighten me.
 

Geo

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Jul 29, 2007
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Is this any good
Geo

Determining the Age of a Tire




When it comes to determining the age of a tire, it is easy to identify when a tire was manufactured by reading its Tire Identification Code (serial number). Unlike vehicle identification numbers (VINs) and the serial numbers used on many other consumer goods (which identify one specific item), Tire Identification Codes are really batch codes that identify which week and year the tire was produced.
The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) requires that Tire Identification Code be a combination of eleven or twelve letters and numbers that identify the manufacturing location, tire size, manufacturer's code, and week and year the tire was manufactured.
Tires Manufactured Since 2000
Today, the week and year the tire was manufactured is contained in the last four digits of the serial number, with the 2 digits used to identify the week a tire was manufactured immediately preceding the 2 digits used to identify the year.
Examples of tires manufactured since 2000 with this Tire Identification Code format:
XXXXXXXX 0600XXXXXXXX 060006 - Manufactured during the 06th week of the yearXXXXXXXX 060800 - Manufactured during 2000
And
XXXXXXXX 0608XXXXXXXX 060806 - Manufactured during the 06th week of the yearXXXXXXXX 060808 - Manufactured during 2008


While the entire Tire Identification Code is required to be branded onto one sidewall of every tire, current rules also require the first digits of the Tire Identification Code (everything but the week and year) must also be branded onto the opposite sidewall. Therefore, it is possible to see a Tire Identification Code that appears incomplete and requires looking at the other sidewall to find the entire Tire Identification Code (the use of a partial Tire Identification Code on the one sidewall reduces the risk of injury to the mold technician that would have to install the weekly date code on the top sidewall portion of a hot tire mold).
Tires Manufactured Before 2000
The Tire Identification Code for tires produced prior to 2000 was based on the assumption that no tire would be in service for ten years. They were required to provided the same information, with the week and year the tire was built contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year.
For example, if the Tire Identification Code on a tire reads:
XXXXXXXX 0680XXXXXXXX 060006 - Manufactured during the 06th week of the yearXXXXXXXX 06808 - Manufactured during the 8th year of the decade
While the previous serial number format identified that a tire was built in the 8th year of a decade, there was no universal identifier that confirmed which decade (tires produced in the 1990s may have a small triangle following the Tire Identification Code to identify the decade). The Tire Identification Code format used since 2000 accurately confirms the year.
And finally, hold on to your sales receipts. Most tire manufacturer's warranties cover their tires for four years from the date of purchase, or five years from the week the tires were manufactured. So if you purchase new tires that were manufactured exactly two years ago they will be covered for a total of six years (four years from the date of purchase) as long as you have your receipt. If you lose your receipt, your tires' warranty coverage will end five years from week the tire was produced (resulting in the tire manufacturer's warranty coverage ending only three years from the date of purchase in this example).
 

Forestboy

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Hi Dick
Copied this from the RVForun so it is specific to US tyres
Pretty sure it's the same as Geo posted

Tire manufacturing date codes
The following was extracted from our RV Glossary Of Terms, compiled and edited by forum staffer Don Jordan.

Generally accepted rules of thumb in the RV world are that, regardless of low mileage or low tread wear, tires should be replaced every 5 to 7 years maximum. Exposure to sunlight, ozone, and ultra-violet radiation causes gradual loss of the plasticizers that keep the tires flexible. Sidewall cracking can often be seen but may not always be apparent. So, for safety’s sake and to avoid sudden catastrophic failure, replacement should be done on an age priority basis. This does not mean that obvious tread wear, sidewall damage, or any other physical problem with the tires should be ignored if they still have “x” years to go before they are “too old”.

The National Highway Traffic Safety Administration (NHTSA) Tire Identification and Record Keeping Regulation, revised July 2, 2000, specifies a new 4-digit date code that must appear on all tires sold in the United States. The complete DOT (Department of Transportation) code is in the following format: DOT MMM SS TTT DDDD where MMM is a 3 digit manufacturer ID; SS is a tire size 2 digit code; TTT is an optional tire type code; and DDDD is the date of manufacture code where the first 2 digits indicate the week of manufacture and the second two digits are the year, i.e. 2802 would indicate that the tire was manufactured the 28th week of 2002.

Note: tires manufactured before July 2, 2000 had a 3 digit date code where the first 2 digits are the week of manufacture and the last digit is the year. Tires manufactured in the 1990’s had a triangle following the 3 digit code, while tires manufactured in the 1980’s did not. i.e. 282 with a triangle would indicate that the tire was manufactured the 28th week of 1992 while if there is not a triangle following the 3 digits it was manufactured in the 28th week of 1982. The newer 4-digit code eliminates any ambiguity in the year of manufacture and allows continuation of the system through the 21st century.

It is strongly recommended that when buying new tires you insist on all tires having the same date of manufacture and that that date should not be more than a few months prior to the date of purchase. Otherwise you will be buying tires that will need to be replaced sooner than necessary.
 
OP
moandick

moandick

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Thanks everybody - super response. I had got it correct but I never did see it in writing - now I feel much happier knowing that what I was doing was, in fact, correct.

Much appreciated, everybody - just goes to show how 'enlightened' this forum is :thumb::thumb:
 
Nov 22, 2007
4,402
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Rapido "A" Class, Mecedes
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18+yrs plus 25+Towing
Tyres

Hi

wow. how quick is that! I posted part of this on ARVM Late last night and to-day we have the difinitive answer (or part of it) Thanks Dick!!:thumb:

However here is the rest of that post as it poses another question:-

Quote:-

We recently had a lot of problems with the tyres on the R-V. Goes back to Easter 2007 when when a rear inner tyre blew out a sidewall on a site in North Yorkshire. The spare went on and I got a new tyre for spare. the big problem is that the tyre size is R8-19.5" which is a crossply size. the logical answer would have been to change to Radials 225?-19.5" However the Rears are too close to-gether and the tyres would "kiss" under load travelling. so I opted to continue with the R8-19.5". Last month prior to leaving for Spain I bought another tyre and fitted the two new ones to the fronts. En-route for Spain we blew out a Tyre (rear sidewall) on the M25 at 2pm! the RAC/Vosa closed a lane to get us off and the Spare was fitted in a layby on the A217. the tyre fitter who did it observed that the tyre was very Old going by the date code on the tyre. so we looked at the outer on the other side and discovered that this was equally as aged. At this point I am on my way to Spain with potentially 4 "dodgy" tyres!!. so I order 4 from "Sinton" to be delivered to me at Amberley Fields where we hole up for the night. To cut a long story short we finish up at Dover after a further sidewall blowout, and having had 4 tyres fitted on a CL and we are OK, and so far we remain so, as far as tyres are concerned as I now have 6 tyres Under 1 Year old on the wheels and the "best" of the old ones on the "spare".

Points to Ponder:- a) How do you tell if a tyre is Out of date? as even the professionals have some difficulty, and reading the (OLD) code is a bit "hit and Miss". (now dealt with inthis posting, Thank you!!) b) How many R-V's with "Dual" rears are running the wrong tyre size? as fitting Metric size can lead to Rubbing and friction generated heat on the tyre. We bumped into a couple at Larroulet who where on their way back to "blighty" who had had 3 punctures ALL on the rear! (and all Radial tyres) since October 2007, It begs the question "had their winnebago been fitted with crossplys new and changed without reference to the effect of said change?"

Something to reflect on if your Rig is older?.

Any advice from the "trade" would be useful too for future reference?


Pete
 

Forestboy

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When I was in Florida recently I copied a checklist from the RVForum.
One of the items is checking the tyres which the Americans are very keen on.
When buying a Rv especially from a dealer they insist all the tyres have the same date code and have an acceptable time left to run or make the dealer fit new tyres.
 

damondunc

Funster
Aug 2, 2007
101
15
near Lincoln
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52
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A class
Exp
9
Beg to differ here but all 8R19.5 Rv tyres have been radials ever since they came out the only crossply rv tyres that I know of were 16inch and 16.5 inch, went out with the ark! you are quite right though that you cannot normally retrofit 225/70R19.5 tyres in place of 8R19.5 the rim widths and offset are different. Many of the earlier 8R19.5 tyres had a low index rating of D which cannot carry much weight and all of the modern ones have a much higher load index of F or G.According to the Michelin tech manual for RV tyres the maximum age for an RV tyre is 7 years with replacement recommended at between 5 and 7 years. I have heard of many instances of 8R19.5 blowouts normally the rear inners due to them running hotter than the outers. Also many RV tyres are permanently loaded at their maximum or overloaded, not good on old tyres.
Dunc.
 
Nov 22, 2007
4,402
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East Yorkshire
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Rapido "A" Class, Mecedes
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18+yrs plus 25+Towing
Tyres

Hi

The R8-19.5 is I admit not "crossply" as I wrongly stated, and whilst still available currently, is getting harder to Source, and only from Michelin although Hankook and Kelly still show them on their listings. I got what where aparently the last 4 on the shelf in the UK as they are on "back order" certainly from my supplier. The tyre has a Tall profile and is narrower on the wheel/road than the 225, having also a different rolling dia. This would make any "mix and match" a "no no". When I looked into it I actually checked the LOADED (static) gap between the tyres, and calculated that with the same loading the 225 would require a larger distance between the wheels to give the same gap between the tyres. Hence my decision to stick with the R8.

What is not clear is wether SOME R-V's Might have been fitted with 225's ON THE REAR as a retrofit without Changing the wheel(s) for ones with a greater offset, which is the only way I can see of safely doing a retro-fit on mine.

It would be Very expensive to replace ALL the Wheels AND tyres, and shall we say the "less scupulous" might not bother?. So if you have had a series of rear blowouts and there is no other aparent cause (as in my case, AGE) then it would appear to be prudent to look at the possibilty of a wrong fit?.

As a side issue the change of rolling dia would also affect the speed indication/calibration (the smaller dia needing more turns per mile)

Food for thought?

pete
 

damondunc

Funster
Aug 2, 2007
101
15
near Lincoln
Funster No
52
MH
A class
Exp
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Try sinton tyres near milton keynes, they stock most of the american RV sizes and I know they stock 8R19.5's in a brand called cooper which have a much flatter tread design as compared to michelins and may be cheaper.
Dunc.
 
Nov 22, 2007
4,402
5,307
East Yorkshire
Funster No
900
MH
Rapido "A" Class, Mecedes
Exp
18+yrs plus 25+Towing
(more) tyres

Hi Dunc.

I (allegedly) had their last 4 off the rack, and they only had the Michelins, I am now short an arm and leg!! and dripping molten plastic!!, the only good side is I used my CC club credit card and can look forward to a free CC site night!!! ( and I have 6 NEW (2007) tyres under me, here in Espania) The trick with tyres I feel is to "keep 'em movin" standing tyres suffer, And I suspect that many R-V owners who sit on sites all winter could be running "deteriorated" tyres without realising it?. If my recent experience has taught me anything it is that when BUYING have the tyre age checked and if neccessary Use that fact in negotiations!!. 6 tyres @ 250 notes each fitted is a big wedge!.

My trouble stems I think from the fact that, management fell for the coach layout etc: and we made a quick decision, this has led to a lot of cost over the nearly 4 years we have had it, Including a NEW gearbox!!, (Failed output shaft) Refurbished Braking system, and exhaust, (without the tyres) And I have recently unearthed some paperwork "lost" inside the manuals which suggests that the coach spent a large amount of time "Static" in Southern France. which is not the best place to be at certain times of year. So if the tyres where exposed to sunlight AND stationary for long periods, this added to the AGE of the tyres will almost certainly be why I have had my recent problems, and under use of the brakes, could be (is) worse than using them, hence the brake "sticking" etc I experienced (2006/7) when the disks where changed and the calipers refurbed.

The Coach has been on the weigh bridge (front and rear) and is within the Limits for both Chassis/axles and tyres. The weighbridge unfortunately cannot cope with weighing the wheels individually, the whole rig with "toad" is just under 8.2t. The only thing we have added to come out here is the wifes Mobility Scooter which rides in the "toad" anyway. So I am stuck with tyre age being at the bottom of my recent troubles.

Hopefully now in the past!!

Pete
 
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