I just spoke to my machinist. His recommendation is based more on Cummins engines, but I thought I'd share:
- 15-20 minutes running at 1500-1700 RPMs, parked w/ no load, to check for any issues before hitting the road, let it cool and check for any loose parts
Interested in others' thoughts but I think this is far too long with no load.
I've always had good results with making sure everything is snug and fluids are full, start-up and check for leaks, hitch up a trailer with a couple of tonnes on it and go for a couple of hour drive at varied speeds and RPM, not over-revving or lugging the engine but making it work. Also x2 on the overrun driving being important. About 80,000 trouble free KM on the above, driving 5 mins across town, quick check for leaks, hitching up trailer and going a couple of hundred km whilst watching gauges like a hawk. This particular engine is a commonrail 5 cylinder but the cruisers have been given the same treatment.
No oil use at 15,000 km intervals and less than 50ml of oil in the catch can at 15,000 intervals.