Maserati Granturismo S - porous alloys?

[2.5pi]

..got a slow flat after only 1 month & 300 miles, no evidence of puncture, anyone else experienced the same problem , alloys are 20" birdcage BTW

[GTS440]

Had a 4.2 last year with birdcage alloys. Did 4000 miles and never experienced loss of pressure.

Have you checked the valve is not leaking?

[2.5pi]

thanks ...i had a 4.2 for 2 years prior to changing, it had fixed metal valve stems whereas the new car has a flexible rubber doobry which might be the cause of the problem, i'll check.

[GTS440]

I'm now driving a GTS Auto, only 1600 miles so far but no problems either and mine's got the newer valve stems too, the ones with a smarter silver hexagonal cap.