Just took my car down for an MOT and I asked them to check my tyres out while it was there, I was told the issue with my leaking tyres is due to the wheels, not the tyres. This is on an old 2003 Mondeo. One of my tyres will go flat within 2 weeks if not pumped up every few days. I have some more minor issues with 2 of my other tyres. I was told either to change the wheels or take it to a specialist who can re-shape (not sure of technical term) my existing ones to fix them. 

Any suggestions on what is best out of those 2 options ? Any temp fix to stop it leaking due to the wheel ? I plan on keeping this car another 2 years, but am fed up having to pump up the tyres twice a week just to keep it above 30 PSI.

Also any way to tell if photo attached here is of an alloy or steel wheel ? 

Thanks !!

Hi, it's an alloy. It's quite usual for alloy wheels to become porous with age. A half decent tyre place can paint latex or some such liquid on the inside of the wheel to reduce the porosity and pressure loss, tho' it's not 100% effective, it helps reduce the pressure loss. (this is in addition to putting sealant around the bead) I know someone who fixed it themselves by squirting diluted pva adhesive into the tyre thro' the valve (they removed the core first) got a local car breakers? Pop down and see if they've got any Mondeo alloys for sale...you should get a fiver each for the old ones, scrap value. 

Normally it's corrosion on the beads,  easily removed and sealant applied,  not expensive any wheel refurb place should be able to do it, you can even do it yourself if you get the tyres off, my garage did it for me one a day.