Hi, Can anyone please give me some advice regarding tyre pressures.
We have a Sterling Eccles Sapphire 1999, and the tyres are 175 R13 94N. I have searched the internet but cannot find this size and therefore the correct pressures.
Our Citroen Picasso's tyre pressures are front 31psi and rear 33 psi. For the rear would it be advisable to increase this by about 5 psi for towing?
Many thanks - from a newcomer - learning very fast!
Caravan tyres don't usually get a lot of use and thus don't wear out, however they do get old and cracks can appear if not changed after no more than the recommendation period which is five years.
For ease of a calculation lets assume your Caravan weighed 800kg empty when manufactured and has a Max Load capability of 1000kg, your tyres then need to be able to carry 500kg each.
The general advice is to go 10% above so 550kg each, this equates to a tyre with a load index number of 87 (545kg) or above. Once the correct set of tyres are fitted, then the correct pressure can be calculated. This is based on the maximum weight and pressure printed on the side wall and the actual maximum weight of the caravan, the equation is:
Weight of Caravan times a single tyre pressure divided by total weight tyres can carry.
So based on that, a 175x13 8ply, load index 97 or 730kg at 65psi, your vans tyre pressures assuming it is 1000kg would be:
1000kg x 65 / 1460 = 44.5 or for round figures 45psi
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Mick + Tina
Good Bye To Our Abbey Spectrum 520, Hello To Our Elddis Crusader Cyclone
Quote: Originally posted by shaunahoney on 24/7/2007
We have a Sterling Eccles Sapphire 1999, and the tyres are 175 R13 94N. I have searched the internet but cannot find this size and therefore the correct pressures.
Your tyres sound like 175 R13C 6ply commercial van tyres which have a load/speed index of 94N, this is 1340kgs per pair at 87mph
pressure/weight per pair are, 36psi/969kg, 40/1046, 44/1136, 48/1210, 51/1268, 54/1340
numbers in red are considered too much for caravan use and should be avoided.
British Rubber Manufactures tyre pressure chart for popular caravan tyres here
most newer caravans have a little silver badge or sticker, possibly on the outside near bottom rail near door. this should give max loading weights etc, and tyre pressures.
not easiest to read though, the text is imprinted like a car vin plate.
shaunahoney - I am not being funny but your tyres are 8 years old they may look in good condition. But you need to change them - it really is so dangerous to try and use them do not use them when older than 5 years. Its not the harm you do to your self its the harm to others if you have a blow out at speed on the motorway.
The chart Gary has a link to is interesting , my latest caravan has 175r14 99 tyres on it , the caravan has a mtplm of 1500kg and a pressure recommendation of 65psi at 1500kg .The tyre maximum pressure is 65psi as stated on the side wall .
So ( the way i see it ) even though the British Rubber Manufactures tyre pressure chart advises against running the tyre at it's maximum the caravan makers seem to be ignoring this advice . Is there a reason for this ? are they putting us caravaners at risk while towing ? Or am i missing something .
Hi, Thanks for all the replies - all helpful. I need to check the tyres - at the moment caravan by the side of the house and not easy to get at the tyres until we pull it out tomorrow. However, I am sure that the tyres have been renewed and are not 8 years old. We checked this when we bought it and the tyres are in excellent condition, with no cracks, etc.
Tyre pressures are always quoted per tyre so no you don't half them, and yes 1180kg on those tyres is 46psi perhaps 47psi
Wiz, I really don't know the answer to that but cost is in there somewhere I'm sure. Plus while a tyre is new it will cope, like everything though age after a rough time in youth will take it's toll prematurely
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Topic: Tyre Pressures
