Yeah, I put diesel in mine last change.
So far I haven't really noticed and difference but it's a 1300 and only got 28,000 on the clock. I have noticed, when checking thru the viewing window, that the oil seems a lot dirtier than it was with normal oil and as someone said, diesel oils have more detergents in them and maybe it's doing its job and giving the motor a clean-out.
I may go back to normal oil at the next change, to see if I can notice any difference, and then maybe put diesel in every third or fourth change just to give it a clean-out. Don't know yet, still thinking.
Take care all,
Dave R