Are you changing your oil too many times ?

i have always gone 8 - 10,000 km on my daily drivers (Hondas or Toyotas) with a filter every second change.
..all have gone 250,000km + and although down on power none smoked.
..i wouldn't stretch the mileage that far with my old muscle cars,but at 2000 km or so a year i' don't change it every year.