Tyre pressure confusion--again!

[Grimsbygranny]

Good morning, just been reading the threads about tyre pressures and need some clarification!
I have a 2019 Ducato PVC and fully loaded it weighs 3210kg. The tyres are Continental Vanco 225/75/16 CP.
The Fiat suggested pressures on the door frame are 5.5 all round, and the ones suggested from Continental are 3.0 all round.
This seems to me a HUGE difference so I'm asking which to go for, please.
I have them at present, some where in between at 4.3 front and 4.8 rear (suggested by son in law who drives a work van) but I would like some clarity on a) why the difference?
b) will the van be safer at Continental recommendations or Fiat?
The ride is quite 'bumpy' at present but I'm a bit scared to let all that air out!

Thank you in advance,

 

[Just smiffy]

From the horses mouth....

 

[Grimsbygranny]

Thank you @Justsmiffy, I now understand and will adjust accordingly (after I have weighed rear Axle!)

 

[Hettie's Crew]

Page 82

http://blobs.continental-tires.com/www8/servlet/blob/85806/e0854f2c7866c64da551474b998ef8b3/download-technical-databook-data.pdf

 

[Grimsbygranny]

Of course, now I have another query--- the tyres are made in Czech Republic, and I cannot find a date number anywhere on them. According to Continental (and thanks Hettie's crew for the booklet) it should be 4 letters in an oval circle somewhere near the DOT sign, but on these tyres no numbers just HWN9 and ETF --have I got duff tyres on my new van???

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[Marmite]

Have you looked on the inside tyre wall, not just external?

 

[Grimsbygranny]

I'll try the inside wall tomorrow--- too wet to lie on the ground today

 

[Just smiffy]

Your looking for this...
In this case week 26 year 2016

 

[Lenny HB]

I'll try the inside wall tomorrow--- too wet to lie on the ground today

In my experience they are always on the inside wall, I wonder if they fit them deliberately that way so it's easy to plam off old tyres.