It depends entirely on the quality of the tire (tyre) which relates diretly to the cost. Less expensive tires can be purchased here in the U.S. that are warrantied for 40,000 miles, while top of the line Michelin or equivalents tires costing much more are warrantied for as much as 80,000 miles. The care, such the inflation you mention, but also alignment of the front end can affect the wear...
As said, depends on loads of factors, but I was once told that you should be able to get 30,000miles out of a set on a car. Best I have done was on my old DAF95 artic tractor unit. I had Michelin MXD's on the drive axle and got 600,000km (370,000+ miles) out of them (with one cut at about 450,000km). I was amazed!