Mazda van 1800e 2004 tyre pressure with load - Mazda Cars & Trucks

on the decal on the door pillar drivers side
talk with a tire retailer as they have the pressures for the brand of tire you are using

I can calculate it with spreadsheet I made, call myself tyre-pressure specialist nowadays.
Depends on tyres maximum load and Pressure needed for that ( AT pressure 6pr 55psi/3.8 bar, 8pr 65psi/4.5bar or 69/70psi/4.75/4.8bar). and maximum speed of tyre given as letter mostly N to R for caravans.

Then from Caravan MPVW ( max permissable Vehicle Weight).
Or better real weight ( overloading is more rule then exeption and unequall load is possible.

But normal car tyres or XL/reinforced/Extraload are sometimes OK if they have enaugh maximum load for MPVW.
Will try to make picture of example.

you should be running 8 ply tyres on the vehicle to carry the maximum load as required by the regulator
The recommended tyre pressure will be on a decal attached to the drivers door ( probably on the door frame under the latch)
Having said all that I recommend 45 psi for the rear and 40 for the front
If you run any less ,the ride will be smoother but if you load the vehicle, the rear tyres are under inflated and prone to failure from overheating
tyres are manufactured to run at a certain pressure due to the construction of the case. Talk to a tyre shop as to the pressure you should be using for the tyres.

Depends also on the kind of tyre.
For the maximum load of tyre nex kinds need next pressure , wich is called AT-pressure/maxloadpressure/reference-pressure , for up to maximum speed of tyre or if lower 160km/99m/h. This is not the maximum pressure of tyre.

Normal car tyre /standardload AT 2.5bar/36psi ( exeptions as low as 2.2)
XL/Reinforced/Extraload AT 2.9bar/42psi ( exeptions 2.8 and 3.0)
6PR( plyrating) /C-load AT 3.8bar/55psi EUR ( USA 50psi/3.4bar)
8PR/D-load AT 4.5/4.8 bar/ 65/69/70 psi
From E -load is not often used in Europe.

From this AT pressure you can calculate the needed pressure for lower loads . Made spreadsheet for it in wich I first add 10% to the assumed load before calculating.
Will give example picture

I would be running at 28-30psi for this set up. If you are carrying extra load in the van up to 32 psi.

Follow the link https://www.conti.nl/wp-content/uploads/2012/01/airpressuretable_pdf_en.pdf

Tire pressure should be indicated on the tires you purchased. it indicates the ideal tire pressure for those tires and it's unsafe to ignore them. but if you do less pressure will give you more grip.

This is a tire pressure monitoring light. Check your air pressure.