tyre advice

[robert_5067654]

Hi all, I have a question about tyres.

Is it ok to fit car tyres onto my van? I have a pair of new BMW mini alloys which fit my caravan perfectly and look great, the tyre size is 175/55/15. The tyres have printed on them 'max load at 54psi 500kg'. I have had my van weighed fully loaded and it came in at 980kg. So are they ok to use?

By the way the tyres on the van now are pirelli P4 165/60/13 re-enforced with no max load printed on them, but my local tyre shop tell me they are only rated at 485kg!!

Any advice appreciated, Rob.

 

[Alistair_5042155]

Absolutely not! Never use ordinary car tyres on a caravan, they must be reinforced and at least 6 ply. Reason - cars have sophisticated suspension systems that take most of the "pressre" , caravans do not so the tyres bear the loads and strains. Also - and I stand to be corrected if wrong - my understanding is that not all alloy wheels are suitable for caravans - some may not simply be strong enough. Check it out carefully, also consider the insurance implications.

 

[rob_jax]

I see the order of the concern expressed by Alistair slightly differently.

Most importantly, the alloy wheels must be designed for caravan use, they are heavier duty than car wheels, and you cannot simply use a car wheel on a caravan without a lot of checking and verfication. Remember that the Mini weighs a bit more than your caravan and it has it's load distributed over four wheels, not just two.

I have a lesser concern about the tyres, caravans often use car or small van tyres as standard fit. You need to make sure that the max load rating on your two tyres exceeds the max van weight.

You can check the load index of a tyre from the numbers following the size, your Pirelli tyres should display something like 165/60 R13 83 - where the 83 is a code for the load index (83 = 487kg) - a web site like http://www.blackcircles.com/general/sidewall can help you find this information.

A final issue is with fitting lower profile tyres to caravans, or rather lower profile than the van manufacturer specified. A considerable part of the van suspension is handled by the tyre walls, and fitting lower profile tyres will have a major impact on the suspension characteristics, and possibly a few broken cups and plates.

Robert

 

[MickC1]

The following web page may be of interest to anyone wishing to fit Alloy wheels onto an Alko chassis:

www.al-ko.co.uk/Downloads/InfoBull14.doc

 

[ProfJohnL]

Fitting the correct wheel and tyre combination is part of your legal obligation. If the caravan manufacture specifies a particular wheel type and size, then to change it takes the van outside of its type approval. Operating a van outside its type approval may constitute a violation of moving vehicle regulations.

 

[robert_5067654]

Thanks for the advice, I've got the message and the original wheels and tyres are back on!

Just a thought, what about all the cars you see with after market wheels and tyres? are they braking the law? what's the differance?

 

[ProfJohnL]

Helo Robert,

I was perhaps a little short with my last posting, some further clarification may be needed.

With regards to fitting alloy wheels to any vehicle, the wheel manufacture should be asked if the wheel is compatable with the specific vehicle's mass and performance. Unless all the criteria are ticked don't use the wheel.

Most caravans will be specified with 6ply rated tyres, you must use tyres that area at least equally rated or better (i.e. more plys)

I doubt if your mini wheels are suitable, and therfore are should not be used.