Just a bit confused about tyre pressures. I thought that the tyre pressure recomended by the manufacturer was to achieve maximum grip and and if the tyres were over or under inflated this could compromise safety. I notice in the handbook you have a choice of pressures, one for comfort and one for ECO. The comfort pressure is 34psi all round and the ECO pressure is 39psi front and 41psi rear. These are for the same load in the car. Wonder what pressure maximum grip is achieved. ??