Tyre pressure

[Chris63]

Hi Funsters
An old chestnut
How do I calculate tyre pressure
I took my fully laden van to a weighbridge
It is calculated as 4.5 ton , it weighed in at 4.1.tons
I now assume that I can carry an additional 400 kg
Can I calculate tyre pressure from that
Regards
Totthedog

 

[Lenny HB]

You need individual axle weight gross weight is meaningless for tyre pressures.
I gave my axle weights to the tyre manufacturer and they gave me the pressures.

As for carrying an additional 400 kg very unlikely most of the spare capacity will be on the from axle.
Again you need axle weights.

 

[Fontie]

When on the weighbridge you should have got your front and rear axle weights, then put these into the link below which would give you the pressures you should be using,

Motorhome Tyre Pressure Calculator | TyreSafe

Our motorhome tyre pressure calculator gives you the correct pressures for your motorhome. Check your tyres regularly for your safety.

www.tyresafe.org

 

[Barclaybasher]

I recently had new tyres to my 3.5t on a maxi chassis. Ran the old tyres at 60psi. The fitter who's spent his life fitting tyres to commercial vehicles said to go to the maximum for the tyre - 86psi. I haven't noticed any difference comfort wise.

 

[Reallyretired]

I have the dreaded Michelin Camping tyres. I run rear at 80psi as per Michelins recommendation and front at 55psi and comfort seems fine. Its the high pressure at the front which causes the hard ride I think

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[dash300]

I have the dreaded Michelin Camping tyres. I run rear at 80psi as per Michelins recommendation and front at 55psi and comfort seems fine. Its the high pressure at the front which causes the hard ride I think

I've dropped my fronts to 65, might drop them a bit more if you are running at 55.

 

[iandsm]

I recently had new tyres to my 3.5t on a maxi chassis. Ran the old tyres at 60psi. The fitter who's spent his life fitting tyres to commercial vehicles said to go to the maximum for the tyre - 86psi. I haven't noticed any difference comfort wise.

Based on experience from my motorhome and the advice I received from Continental and Tyresafe I would suggest that the fitter has been giving the wrong advice for his working life.

 

[DJA]

Based on experience from my motorhome and the advice I received from Continental and Tyresafe I would suggest that the fitter has been giving the wrong advice for his working life.

And that is an understatement.

 

[Pausim]

When on the weighbridge you should have got your front and rear axle weights, then put these into the link below which would give you the pressures you should be using,

Motorhome Tyre Pressure Calculator | TyreSafe

Our motorhome tyre pressure calculator gives you the correct pressures for your motorhome. Check your tyres regularly for your safety.

www.tyresafe.org

That calculator gives my rear axle pressure as 80psi whether I put in 1000kg or 2000kg. Fortunately Carthago supply a comprehensive list of pressures for various weights, sizes and makes and they are nowhere near the pressures given by that calculator.

 

[HugoBNB]

I believe the correct temperature range to check you tryes at is 16-20 degrees. Running temperature will normally increase your pressures by at leat 10%.