Been running MAN engines for several years and found them to be a 2 million km engine with decent serving. You have to be careful of the EGR engines though. Like the Cummins ISX 781, if you keep the EGR system 'in tune' or better still 'switched off' this engine will give you excellent economy and pulling power.
The same applies to the Prostar. From reading the various threads on here there seems to be a lot of ignorance to the diagnosing, tuning and repair of these engines, causing owners a lot of totally unnecessary downtime.
The key to having a successful 'relationship' with one of these trucks is having a good workshop available who can keep the EGR system 'in tune' and sort out the wire chaffing issues with this truck
Internationals are the biggesest peice of junk on the road. Well the 9900i anyways. We have 3 at work. Shift like crap. Dashes fall apart. Uncomfortable to drive. Wiper switch is the stupidest thing ive ever seen. Jumpy clutch. The cabs sway and shake. They ride like crap. Only good thing about them is they have 3 cup holders and if they have 4 way lock up the have good traction. Whoever designed these trucks needs to go back to coloring books.