I agree with Max.

Bought my car a year ago. First diesel. The car had barely been driven for 2 years before I took possession. Within a few hundred miles it was barely able to get out of its own way. I changed the filters and that helped, but it was still a pig.

I ran Lubri Moly through it and the car got a new lease on life. The clear hose I attached quickly went BLACK as the crud 'cooked' (?) off the injectors. The idle smoothed out and the engine got quieter. Its also significantly more powerful. Needless to say, I was very pleased. That was about 8000 miles ago. No issues since then besides a dirty first stage filter that caused the idle to lope a bit.