Tyres deflating too quickly

[hooba]

Wasn't this a problem with the MK5 Golf too? I remember it coming up in the Wheels long term term of a Golf Mk5, and it mirrored the problem I had with my car (not as bad as what the OP has). When I changed the tyres due to wear, the problem went away.

I'd get them remounted.

[MACCAA]

Time to apply a little logic here.For all four tyres to go down the SAME amount of 10kpa is ahem "highly unlikely".
We're talking about less than 1 1/2 pounds difference here from the original pressure.A difference of 10 degrees in the outside temperature is worth around a one pound difference.
Driving the car can easily raise the pressures four pounds or so,fast driving a lot more.
So unless the tyres were checked at the same temperature,and the same condition-[ie dead cold] I don't think there's anything wrong here at all.

[darkfriend]

Thanks everyone. Great suggestions. I have Continental Sport Contact 2's, and they are losing 10kpa (not psi) every five days. If it was just one wheel I'd understand and look for a specific leak... but it's all wheels. Wierd. I check them when cold and top-up when cold.

I will probably need to take them to a tyre place and have therm checked after I try that detergent spray trick!

Thanks for all your help

[brad]

I had CSC2 on my Octavia & I didn't notice an issue with tyre deflation...... BUT!
a) I only ever check my tyres every month or two
b) I usually inflate them to 36psi
c) I really don't worry too much if they dump a bit of pressure. I just put that down to inaccuracies in the digital gauge at the various service stations I use.
d) I've given up on the 3 pencil gauges at home as they tend to vary a bit
e) Gave up on buying decent analogue gauges as they break if they get dropped (woops $25 down the drain).

It's a bit like checking your oil - don't ignore it completely but don't check it weekly either. You'll just go insane.

[markwid]

I use my old but trusty snap-on pressure gauge to check monthly.

[prise]

...Bloke reckoned nitro would fix that (molecules are bigger than oxygen)....Apparently nitro is more stabile as well as runs cooler so handling is better....

Air is 78% nitrogen and 20%oxygen so if the bloke at BJ was correct then all you would have to do is wait long enough and the oxygen would escape leaving the nitrogen behind - the bloke at BJ is talking BS. It's not the oxygen that causes the problems (unless you're tyres are smoking hot) it's the water vapour or humidity in the air which causes the pressure to vary more with temperature than it would if the air was dry. That's why race teams use nitrogen, it's guaranteed to be free from water vapour because of the way it is extracted from the air and they are trying to minimise pressure rise/fall as tyres heat/cool.

Compressed air that has been dried is fine for 99% of use.