Tyres year of manufacture

[Douglas_374404558]

HI! All can anyone refresh my memory how do i find the age of my caravan tyres just bought a brand new Swift charisma 550 and think it has an 03 pair of tyres on it ???? cant remember the numder combination to workout the year/month

thanks Duggie

 

[Sproket]

Duggie

Take a look on here ( page 4 )

http://www.tyresafe.org/data/files/caravan 08.pdf
Sproket.

 

[Douglas_374404558]

Duggie

Take a look on here ( page 4 )

http://www.tyresafe.org/data/files/caravan 08.pdf
Sproket.

cheers Sproket thanks a lot

 

[machighlander]

Hi sprocket,

i have recently checked out my tyres after looking at that site,

mine don't seem to have the number on them anywhere.

They are Pirelli Citynet 195/70r 14, it says on the markings that the max load is 615kg and the max pressure is 44psi.

My caravan has a weight of 1360kk, so are these tyres not suitable ?.

 

[machighlander]

Oops, typo, the weight is in kg, not kk.

 

[Lutz]

The max. load marked on the sidewall in kg (or lb) applies only to the US market. For everywhere else, the max. load is identified by the number after the size marking, e.g. 195/70R15 C104R (104 = 900kg max.)

In your case, with a 1360kg caravan, you would need tyres with a load rating of at least 95.

 

[gary]

The tyres between then carry 1230kg at the maximum pressure of 44psi, your van weighs 1360kg, so, you either need to increase the pressure beyond the maximum to suit, or you are overloading them and therefore running them under-inflated at the designed maximum pressure.

Clearly then as either way is not safe they are not suitable, the tyres ideally should be able to carry 10% more than the maximum weight of the van.

In your case, 1360+10% is 1496kg or tyres with a load index number of 97+

Again more information on Tyresafes website;

http://www.tyresafe.org/data/files/caravan 08.pdf

 

[Sproket]

Highlander

I'm no genius but if the figures you have put on here are what's on your tyres, my rear would be nipping...

Max load 615kg ? that's only 1230kg for both & your van max is 1360kg ?

I can't find that size tyre on the Pirelli site ?

http://www.pirellityre.com/web/catalog/car-suv-van/catalogo_sizerange.page?categoria=/catalog/car-suv-van/van/none&uri=/pirellityre/en_IT/browser/xml/catalog/car-suv-van/VAN_Citnet.xml&prodotto=119530&vehicleType=CAR-SUV-VAN
I would be tempted to remove one and have a good look at the other side for all of the markings,

You need to find the load index , it will be on there also year of manufacture, I don't know how old your van is, but there is a possibility that the tyres are older & may need replacing in the near future.

Sproket.

 

[machighlander]

Hi Sprocket, my van is a 2001 Abbey Aventura 316, the tyres are certainly pretty new looking to me, definately not the originals. Also, had another look and there is a number 91T after the size stamp, does this mean anything relevant. I also seen the max weights were specific for the U.S. market. My caravan will never be near the maximum load, it is almost empty apart from the fixed furnishings.

The Pirellis' are stamped as made in Spain, still no sign of year though, and its a wee bit too cold to go out and strip one off.

cheers.

 

[gary]

Tyre date stamps are changed every week so the more accessible bottom die is used and only therefore stamped on one side of the tyre, apart from other safety considerations, the dies are very hot and it's considered to dangerous to struggle changing a top die as well.

It would seem then and unlucky for you, that both your dates are facing inward so a mirror and a torch might come in handy?!

91 T is the load and speed index, 91 not surprisingly represents 615kg's, 'T' is safe at that load up to 118mph.

 

[machighlander]

Cheers Gary, very useful replies there .

Looks like somebody will have to alter their letter before posting it up the lum.

 

[Sproket]

Highlander,

I would be tempted to take it to a weigh bridge ( that's if you have one local ?? ) to find out how much it weighs at this moment in time.

You may be in for a surprise, how much or little of your pay load is left & for the weight loading of the tyres you have on

 

[machighlander]

Sprocket,

nae worries, i am goin to get some new ones fitted in January before our next expedition. I dont think the owner who had this before me knew about these things, as i said earlier they look almost new, he pointed this out to me when i was going over it pre-sale, at that time i had no idea about all the ratings numbers and their meaning. Thanks to you guys i do now though, cheers, this site has given me invaluable info in the short space of time i have been a member, brill.

As far as the tyres go, now that i am aware of the mismatch i won't tolerate it, i am very safety minded when it comes to tyres, brakes etc, have to be when my other love is powerful motorcycles.

This has shown me that there are other checks a prospective buyer should look for when scrutinising a buy, i will certainly pass this on to anyone i know who is in the market for second hand caravans, like i said, i dont think the last owner would have been aware of this either.

Wonder how many folks are running around with mismatched rated tyres.

Thanks to all for your replies.

cheers.

 

[Lutz]

The Tyresafe recommendation to add a 10% margin of safety to the load rating, although not to be criticised, is another case of a safety margin on top of an already existing safety margin. Because caravans are never towed anywhere close to the speed rating specified for the tyres, there is enough safety margin in that alone. (The load rating applies to the maximum permissible load at the maximum permissible speed).

 

[machighlander]

Ok Lutz, enlighten me here.

Going by what yer saying the fitment i have should be compatible ?.

 

[Lutz]

All I was trying to say is that it isn't absolutely necessary to allow an extra 10% safety margin on the load rating, which is what Tyresafe is recommending.

 

[Gafferbill]

highlander ..There are some laws that apply here.

You say your caravan weighs 1360kgs and you say it is fitted with tyres with a load index of 91.

It is illegal to run those tyres above 615kgs each or 1230kgs per axle.

Your caravan must have by law a manufacturer's plate fitted that states the maximum authorised weight of the caravan.

This is usually to be found low down on the near side of the caravan near the wheel.

It is illegal for this plate to be absent or to load your caravan above this weight.

All you have to do is find out the MAW from the manufacturer's plate and divide this by two.

This will give you the load each tyre will need to carry.

You then add 50kg to allow for uneven side to side loading.

Thus if your MAW is 1360kgs ...

1360 divided by 2 + 50 =730 or a load index of 97

... I note that Gary has given you this index in a post dated 4 Dec 2009 01:31 PM

and Lutz has recommended a tighter index of 95 in a post dated 4 Dec 2009 01:24 PM

From the figures you have given, your tyres are illegal and the person who fitted them broke the law.

 

[Gafferbill]

........just to add.

MAW now reffered to as MTPLM

The maximum technically permitted laden mass of the

caravan

 

[Lutz]

To be absolutely correct, you could subtract the noseweight from the 1360kg, because this load is not carried by the axle, and hence not by the tyres, either.

 

[gary]

I just cannot comprehend this subtract noseweight from the axle load business, that's all very well sat still on your drive but not on the move, once moving the noseweight is totally dynamic and will shift from nose to axle and back again on a constant basis...it's called pitching!

In point of fact and by the same token noseweight then increases while on the move, so do we subtract some more weight from the axle load??

Bill, technically it is permissible to overload the tyres provided you keep the speed down, ie a 615kg load at 60mph does not stress the tyre as much as at 118mph (in the case of a 'T' rated tyre) However at what pressure? it's got to be greater.

Tyresafe who are the vocals for the British tyre manufactures frown on this once popular practice of adding a 'speed bonus', their advice is to use that extra capacity together with a further 10%, advice Swift and other manufactures have adopted.

To my mind and simply put, my cars capable of 134mph, I won't ever go near that so the engine and everything else will always be working well within their design capabilities

Seems obvious to me then to apply that to tyres by following Tyresafes advice and get some that you won't be thrashing by expecting them to work near their limit without trouble?!

And then get them balanced!

 

[Lutz]

All limits (towload, axle load, noseweight, etc.) are always based on static conditions. The manufacturer must ensure that an adequate safety factor is provided to cater for dynamic conditions. One can compare it to a lift which is approved for, say 8 people, but the cables, drive system, etc. must be tested to 10 times the permitted load.

Having said that, due to aerodynamics of the caravan, noseweight will nominally reduce with increasing speed.

 

[machighlander]

Ok folks, didny mean to start off a debate between ye all re the legalities and safety margin purposes.

Going by what some of you are saying my tyres are an illegal fitment, others say that they are within the paramaters of the safe margins. If these recommendations from the manufacturers and a third party are based on the caravans mptl, and also at the highest speed permitted by the type of tyre, then surely if like me you are not going to load up with excess kit and will definately not be over 60 mph, then they would easily fall within the safe bracket. After all, is the mptl not the highest weight the caravan is recommended to carry, not many folks will be at this weight.

Dont mean to beat this thread to death, but i will quite easily go out and change them, as said in earlier post i have great respect for safety matters with tyres brakes etc, but sometimes there can be untrue advice that need not be followed.

 

[Lutz]

Whichever way you look at it, a tyre with a 91 load index is low for your caravan. I'd recommend at least a 95 load index, Gary would so far as to go for a 97.