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MG MGF Technical - 5lbs in 8 weeks

I have a TF160 - is it reasonable to lose 5lbs pressure from each tyre in 8 weeks? I did not have this problem with my previous VVC. I realise these are different tyres and just wondered it this was normal?
Jan

Jan
Many cars and bikes over the years and have never lost 5lbs in 8 weeks, provided that I check the pressure consistently.
No wish to offend but: do you use your own gauge or different ones at various filling stations?, do you always check at about the same tyre temperature? (i.e. before driving more that a mile or so).
Sorry if Granny already knows how to suck eggs :-)
If all seems OK then get either supplying dealer or a good tyre fitter to break the rim seal and reinflate and possibly change the valves or cores.
HTH
JohnP

Jan

I go along with JohnP on this one - sounds odd especially if all four tyres have lost the same amount.

Ted
Ted Newman

Always the same gauge and always cold tyres. Just seemed odd that it was 5lb exactly on each tyre. Had not checked the tyres in between. Seem to be holding the pressure now. Except after putting in 26 front 36 rear one front tyre went down to 16lbs - thought it was a puncture but appears to be the valve and I am now concerned if that has done any damage to inside of tyre. Taking it tomorrow pm to have this checked.
jan

I think this has to do with the size of molecules. An oxygen molecule is smaller than a nitrogen molecule, so the first time you fill a tyre with air you can lose pressure.
This minimises over time by refilling with air, since air has about 20 % of oxygen and the oxygen escapes.

At some tyre companies you can have your tyres filled with nitrogen and lose no pressure at all.

Johan
Johan Slagter

Hi Jan,
being a physicist and lazy I (mostly) go for the simple option.

4 tires loose the same amount at the same gauge.
hmmmm.....
Appears that the gauge has changed. Either it was wrong before or is now. You should check with a different gauge.
Ingo

Thanks. Had tyres checked with two different gauges now and they have not lost any pressure since. So hopefully it was just one of those things. Will keep and eye on the pressures though.
Jan

This thread was discussed between 19/11/2002 and 22/11/2002

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