Tyre Pressures

[karlak]

So, having had our XC90 for a couple of weeks now and not done much mileage as yet, thought I better check the tyre pressures, usually a 2 week routine for me. I find that it should 32 psi back and 35 psi front going from the door sticker, for normal loads.. Nope all tyres 42 PSI. I think the dealer forgot to reset the pressure on the PDI....

Positive side is, what a difference now on the drive. Quieter and it doesn't feel like your fillings are going to pop out when you go over a cats eye in the road. Was starting to think the standard suspension setup R-design was a poor choice, but now is all good

[Quacker]

I checked the tyres of one of my cars the other evening and found that they were all far too soft, so I pumped them to around 35psi. In bed that night I thought that it was strange that all four has lost half their pressure since I last checked, so next morning I checked again using another gauge.
Found that I'd actually pumped all four to 52psi. The gauge on the compressor had gone faulty. It had been used by a truck driver to inflate one of his truck's wheels that morning and it probably went wrong or was dropped to the floor or something then.

Straight up to the motor factors that morning to get a new trigger and dial gauge for the air line plus one pocket gauge extra. All is now well.

Just posted this to show how things can go wrong even when tools are occasionally calibrated and generally looked after, and what the consequences can be if one doesn't double-check one's work and especially the work of others.

Do you check your wheel nuts after someone has removed and replaced it? I do. Found several slack fasteners over the years. It's easy to forget a wheel when four wheels have been replaced. A couple of weeks ago I witnessed a truck carrying soil just out of town on a blind corner that had shed two rear wheels on one side. One wheel was thirty yards behind it with a spacer about fifteen and the other wheel was over the hedge somewhere. That was a 'never event'. The police were called and VOSA will have been all over the truck, driver and owner like a nasty rash, and so they should. Driver should check wheel nuts every morning without fail and that should be made easier by having arrow indicators on each nut. It could have killed someone.

[Clan]

Originally Posted by karlak

So, having had our XC90 for a couple of weeks now and not done much mileage as yet, thought I better check the tyre pressures, usually a 2 week routine for me. I find that it should 32 psi back and 35 psi front going from the door sticker, for normal loads.. Nope all tyres 42 PSI. I think the dealer forgot to reset the pressure on the PDI....

Positive side is, what a difference now on the drive. Quieter and it doesn't feel like your fillings are going to pop out when you go over a cats eye in the road. Was starting to think the standard suspension setup R-design was a poor choice, but now is all good

The 32/35 setting is a low one , volvo recommended that just after the XC90 launch to minimise road noise which some people complained about ., before the quieter tyres were developed .
All very good , but if you continue to use these low pressures you risk wheel damage if you hit a pothole and at nearly £1000 for some of the wheels and £200 a tyre it is going to be very expensive sooner or later , also you are guaranteed to wear the edges far more than the centre , for example you could end up with 2 mm on the edges with 5 or 6 mm in the centre ..
Also your fuel consumption will not be optimised , try finding a smooth flat surface , try pushing the car with 32 psi , you can hardly move it if at all , try the same at 40 psi , you will notice a big difference .

What you have are yesterdays racing tyres and they really need around 40 psi to work properly , Try a compromise at 38 psi all round and re calibrate the tyre pressure monitor . Whoever put 42 psi in your tyres was really trying to doing you a favour .
good for you at least checking your pressures , I would say 80% of drivers have no interest at all , and when the tyre pressure warning pops up they just re calibrate them to get rid of the warning ..

The above findings are taken from practical experience with many xc90's and other models I have seen and adjusted tyre pressures on at various mileages .

[gaby]

Some of the remarks made are why I prefer dTPMS.
Unfortunately, volvo doesn't even provide it as an option anymore, giving owners a choice.
The owners manual of MY2019 still says 2.4Bar (35psi) normal use, 2.7Bar (39psi) ECO/fully loaded (all tyres except 20").

[nu11eaf]

I tow a caravan so keep my tyres at 38-39psi but everytime I take my car in to my dealer for service or other work, updates etc I get it back with tyres at 35psi.
I was told that they always put everything back to standard unless told otherwise by the owner.

[tem]

Originally Posted by nu11eaf

I tow a caravan so keep my tyres at 38-39psi but everytime I take my car in to my dealer for service or other work, updates etc I get it back with tyres at 35psi.
I was told that they always put everything back to standard unless told otherwise by the owner.

When handing your car over for Service etc, tell them what pressure you want, works every time for me.
They will add your request to the work sheet.

tem.

[nu11eaf]

I do now. In fact the regular service receptionist knows now and always has a note on the worksheet.