[GrahamBrown1]

Good fuel is the way for a clean engine.

My own personal experience is i run my S80 on premium diesel. It runs around 50mpg and the engine oil stays remarkably clean. I change it at 9K mile intervals half the Volvo interval and it is just about going black by then. It’s the cleanest engine I’ve ever owned going off this. All my other and previous Volvos go jet black instantly but this is the exception. The only difference is this has run on premium diesel throughout my ownership when purchased with 30k miles on. I thought I’d run this one on premium more as an experiment than anything else but hardly scientific but I’ve just sort of kept on with it.

I’d say just carry on how you are, but frequent oil change and good fuel and you’d be fine don’t worry.