Well, I do about 30k a year, and I had the Toyos on for about 8 months. If you do the sums, that is around 20k miles! Incredible, but I swear it.
Of course, the majority of my 30k is on the motorway, so I'm not hairing around corners all the time, which would reduce the tiry lifetime I guess. I was well pleased with the 8 months.
I made sure I swapped them front-to-back after about 6 months, since the fronts wore down quicker.