I have a ford ikon with 14" Pirelli tubeless tyres. The problem is that whenever the vehicle is stationary for 2 or more days, the tyres flat out. Also even when driving I have to refill one of the tyres every 2 or 3 days. I asked a tyre expert but he recommends me to fit a tube, which I don't want to. What is causing the problem and what is the solution.
Thank you.

Hi, I have had this problem with UK Rover wheels. It was proved that the width of the wheel (7J) as wheels are only fixed at one end was not strong enough to support its dimensions (it went oval with the weight of the car.) I did not want tubes either so had a sealant added to the rim before the tyre was re-fitted. Cured my problem for the life of the tyres. I had to have 1 wheel re-sealed after a flat was repaired. Walke40

It is one of three things:-

1. Tyre leaking
2. Wheel rim leaking
3. Valve leaking

If you have a big tub, Fill with water. Put wheel/tyre in tub, check for air bubbles, this will be where leak is. You can check valves without removing wheel, use washing up liquid (not much ) pour into valve, look for bubbles.

I take it the lacquer is not damaged on the wheel finish as air can leak past none adhered lacquer and the wheel itself

You don't say how old this car is? I have seen wheels rusted and a new tire would not properly seal. The fix is to dismount the tire and clean the bead of the rim. In extreme cases I have used some grease and it has worked for a very long time. You should probably take the tires to a good tire shop and have them check for leaks. Could be as simple as a nail in the tire.