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Correct tyre pressure

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Correct tyre pressure

Just been checking out the correct tyre pressure settings for the Zafira prior to the off on Sunday and am a little confused.
I've attached a screen-shot from the manual.
There'll be three adults as well as large wheel chair and three large suitcases of which one will be in the roof box.
In the screen-shot for up to 3 people it shows the pressure should be either 29psi (or 36 for more fuel economy) on each tyre yet a full load indicates that the front should be set to 30 and the rear to 38. I assume that the rear needs to higher because it is expected that most of the excess weight would be contained at the back. But what about the roof box? It is set more forward that I expected due to where the fixing mounts are.
So, should I still set the pressure to 30psi and 38 psi or would it be wise to increase the pressure at the front a tad?
I did find this which offers a different view.

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Re: Correct tyre pressure

The ECO option is supposed to give you better mpg (harder tyres, less rolling resistance) but it will also make the car feel like it's running on a washboard. Stick to one of the other two options according to your loading.
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Re: Correct tyre pressure

Well, when I got the garage the front tyres were 34 and 37and the rear were both 37.
I upped the back to 39 and leveled the front at 34.
I hope that works out. Drives fine unladen so we'll see on Sunday.

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Re: Correct tyre pressure

Now you have me wondering if you put 34psi in a cold front tyre and go on a run warming up the tyre what would the pressure be then Undecided
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Re: Correct tyre pressure

Quoted inflation pressures are always for 'cold' tyres, pressures will increase with higher temperatures (how much will obviously depend on how hot the tyre gets), I don't know how hot tyres actually get in operation so I couldn't comment on how much the pressure would increase.  If I remember correctly the pressure will be roughly proportional to the absolute temperature.
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Re: Correct tyre pressure

@Mav:- have a good trip Roll eyes
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Re: Correct tyre pressure

Yes, safe journey.
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Re: Correct tyre pressure

Thanks for the good wishes.
Unfortunately, things aren't now going as planned Sad
The main purpose was to take my 85 year-old mother away as she rarely gets out these days due to crippling osteoarthritis. But this morning she declared she's too unwell to go and no amount of persuading would make her change her mind.
She insists SWMBO and I still go but that doesn't particularly feel right. The upshot of this is that my daughter and her mother will help look after mum while we are away but just a week rather than the two weeks we had planned.
Still not feeling that good about going but everyone else insists we should.
Luckily it's only Torbay so we can get back relatively quick should the need arise.
Edit : wrong smiley Cry

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