I think the problem arised after I put the pressure front 34psi rear 37psi! But I'm not sure what the pressures should be, as the tyres area recognised size for the car
If you put a line of chalk across the treads and drive back and forth a few times on a flat spot (e.g. car-park) then if only the centre part of the line vanishes first, the tyres have too much air in.