Ours has a TBO of 1800 hrs and it was over 1600 when we bought the aeroplane. As it needed a shock load inspection anyway we decided to zero time the thing too. We're also going to fit an EDM930 or similar to keep track of temps and shock cooling and set warning limits (i.e. MP) so I hope we get close to TBO next time as I'd rather not spend another £28,000 too soon!
Ironically you can buy a Turbo Normalizing kit for the Commander so that you don't overboost, BUT....it is not certified under EASA as clearly it is unsafe...right? (Come to think of it I don't think the EDM930 is certified under EASA either...all good reasons to change state of registry
....)....