tyre pressure 175R13C

[Adrian_374423572]

does any one know the pressure for these tyres based on a 1150kg swift 490 caravan. Keep getting different pressures from different web sites.

Any help most welcome as going away this week end for the first time

 

[Gafferbill]

The max weight loading and at what pressure should be stamped on the tyre wall.

Your 1150kg Swift plus the payload with that size tyre will be running near the tyres maximum.

Needless to say the tyres have to be in good condition to cope!

Your Swift is similsr to my 440 with the same tyre size.

I use 50psi.

 

[Adrian_374423572]

The max weight loading and at what pressure should be stamped on the tyre wall.

Your 1150kg Swift plus the payload with that size tyre will be running near the tyres maximum.

Needless to say the tyres have to be in good condition to cope!

Your Swift is similsr to my 440 with the same tyre size.

I use 50psi.

thanks for that, the tyres are in good condition but not to that pressure, I will give them a little extra to night.

thanks

 

[JimC1]

We had a 1994 vintage 490 with the same tyres and they had 50 psi in them.

 

[xtrailman]

Adrian

Why not email swift?

My last van an Avondale was 33psi

My present bailey 42psi

So pressures do vary, obviously too high a pressure is preferred to too low a pressure, broadly speaking.

 

[Adrian_374423572]

Adrian

Why not email swift?

My last van an Avondale was 33psi

My present bailey 42psi

So pressures do vary, obviously too high a pressure is preferred to too low a pressure, broadly speaking.

thanks for all your help.

I did speak to Swift today and for any one else out there with the same question the pressure should be 50 psi

thanks for all the help

Adrian

 

[TrevorM]

Adrian, thanks for asking this question; I was thinking of doing the same for my Elddis Tornado Vogue with the same size tyres and the same MTPLM. I believe in my case, some of the confusion exists because no-one seems to make the original 175 RR 13 LI89 (reinforced) radials, for which my handbook recommends 42psi.

I have just fitted similar 175 R 13C tyres with a LI of 94, and do not believe the original 42psi will be sufficient for these. I have printed a chart from the web (somewhere!!) which suggests that around 49psi would be correct for the same size tyres with a LI of 97.

In the absence of any better information (any suggestions anyone?) I shall set my pressures at 50psi as your last comment suggests. Incidentally, I would be interested to hear what the Load Index is for your tyres, since this will affect the required pressures.

Enjoy your holidays,

Trevor M

 

[xtrailman]

This site may be of interest, gives you the actual load for the idex number

http://www.tyresave.co.uk/tyreload.html

 

[gary]

Pressure charts as well as other information specific to tyre fitted to caravans;

http://www.tyresafe.org/data/files/TyreSafeCaravan.pdf
Quite right about reinforced tyre pressures being lower than 6 or 8 ply commercial tyres, reinforced max is 42psi while 6ply is 54psi and 8 ply 65psi or occasionally 69psi.

The reason is, a given weight requires a fixed volume of air to support it, the space inside a tyre, it's volume, varies depending on it's overall size and construction. Therefore the smaller the space inside the tyre, the greater the pressure needed to shove all the required air inside.

 

[xtrailman]

Pressure charts as well as other information specific to tyre fitted to caravans;

http://www.tyresafe.org/data/files/TyreSafeCaravan.pdf
Quite right about reinforced tyre pressures being lower than 6 or 8 ply commercial tyres, reinforced max is 42psi while 6ply is 54psi and 8 ply 65psi or occasionally 69psi.

The reason is, a given weight requires a fixed volume of air to support it, the space inside a tyre, it's volume, varies depending on it's overall size and construction. Therefore the smaller the space inside the tyre, the greater the pressure needed to shove all the required air inside.

Gary

i've downloaded that pdf, cheers.

 

[TrevorM]

Gary, thanks for the link. I had previously downloaded a very similar document (possibly an older version of the same one,) which did not have my LI of 94 included. I can see from 'your' version that for my 6 Ply 175 R 13 C LI94 carrying 1150Kg, that a pressure of 45psi should be adequate.

Thanks again.

Enjoy your holidays,

Trevor M.

 

[gary]

Yes there are two versions and I have a copy of both, not sure which one is which though?!

For older sizes, I've also got the original chart from their booklet, this shows tyre diameter which can be very useful for selecting altenates where originals are under rated load wise, see here;

www.arcsystems.biz/Pictures/tp.jpg

 

[Gafferbill]

Adrian the original poster spoke to Swift for advice....

This advice was buried in a comment...

I hope he does not mind if I make it more prominent

Adrian said :-

"I did speak to Swift today and for any one else out there with the same question the pressure should be 50 psi"

thanks for all the help

Adrian