New crank sensor fitted, (real one) and changed the oil n filter,,,, was 87miles over the 10k, I was worried as it was over the 10k, but I lived to tell the tale,..
Seems high mileage between changes, given the price of TC oil. 
It's still expensive when you change it unnecessarily. The 3-4k oil change suggested here is utterly pointless on a petrol engine, especially when using high quality(or even low quality) semi-synthetic oil. An annual 10k(ish) change makes perfect sense to me.
Thing is, I know that (as of about 7 or 8 years ago) no oil for car engines lasts more than 7k, and that degradation starts immediately.
So to me it makes absolute sense to change it around 5k as a decent compromise between (the negligible, on an Omega) cost and taking the oil to the point where its lubrication properties are diminished.
On a petrol, I generally take this at the point it changes from clear to treacle brown.
Obviously with tractors, 6k is ambitious for anything, not due to the oil degradation, but the abrasive particles trapped in the oil.
But it's everyones individual choice.
