Tyre Pressures

[Smudge345]

Hi Folks

 

I recently bought an old Herald Valencia which has really been well looked after , she's on a Transit 2.5TD LWB chassis and has a full laden weight of 3300kg.

 

The previous owner has left loads of info with the original handbook for the heating and water pump etc, what's confusing me is what the supposed tyre pressures are , they have in the handbook , hand written Front 41 psi and Rear 53 psi fully laden , personally i think this is way to low as the tyres always look softer than they should be compared to other motherhomes , any advice, help suggestions will be greatly appreciated , i'm a newby to motorhoming.

 

Tyre sizes are 225/70R 15c

 

TIA

[crocs]

With that size of tyre and the sort of weights involved, your pressures may be about right (although I don't know the weight on each axle). Front definitely OK although wouldn't harm the rear to be at 60psi.

 

But, someone more knowledgeable than me will comment.

[Robbo]

The pressures sound about right for the tyre of type and chassis weight.

 

If you assume a front axle load of 1500Kg and rear axle of 1800Kg you're looking at 37 front and 46 rear based on a load index of 109.

 

Best to take it to a weighbridge and weigh each axle fully loaded - then contact, say Continental Tyres by email and they will send you the appropriate pressures.

 

In the meantime I would err on the safe side and use the pressures as given to you by the previous owner.

 

Perhaps you could confirm the load index marked on the tyre and the maximum permissible loads for each axle as shown on the vin plate.

[EJB]

My AT Tracker, which isn't quite as old as your vehicle, but 3400KG runs on the current Michelin Agilis Campers at 50 front and 55 rear (PSI)

These was the recommended pressures by Michelin before they defaulted to 80PSI for rear axles a year or so ago.

There are Tyre pressure tables on the internet if you weigh your vehicle.

 

PS. 'Camper' tyres have heavy duty side walls to allow for being static for long periods.

 

[david lloyd]

I would do as Robbo suggests and take the vehicke to a weighbridge fully laden as if you were going away (including passengers if possible) then contact the technical department of the tyre manufacturer who will be able to give you definitive pressures based on the axle weights and tyre type/size. Often these are lower than those given by the bad vehicle manufacturer as they are normally quoting a figure for all types of commercial use.

 

Getting the overall and individual axle weights will also allow you to make sure you are within the payload limits of your vehicle - these will be stamped on a plate usually under the bonnet or affixed to the door pillar. It is important to stay within these limits to be legal and safe.

 

David

[monique.hubrechtsgm]

On average the inclination of the Tyre is 3 cm at 850kg. That is a real visible fact on the ground. But front and rear have different load effects. Keep a spread of .75 bars between F/R. Irrespective if your nose is down or not. In the UK you are down plated to 3.5 kg because of car licence for a fiat 35 L capable to run 4.0 kg. Westfalia a German famous Van manufacturer built only on fiat maxi and a decent payload for b- drivers. They built also built on fiat Mercedes sprinter and Vito including 4wd. Full air suspension is available on all their cars.in that case you can not be seen as overloaded be cause air keeps you on preset drive height. Only your tires should have the correct pressure. I just look at them.