China don't ascribe to ULSD or anything else enviromentally correct (or at least not what the rest of the world deems enviromentally correct), one reason I refrain from intentionally purchasing anything made in China voluntarily (some items you are stuck with Chinese orign because it's only made there....)
Far as deisel engines are concerned, internal wear (cams, cranks, journals and moving parts) aren't effected by ULSD but injection parts (pumps, nozzles and associated parts are).
Internal moving parts are best protected by a quality lubricant, any one of the multi-grade diesel lubricants such as Rotella or Delvac. Therein lies the rub. You have no idea if the internals were made to specification and/or if they are of quality manufacture. That's all in question.
Pump wise, I would add either Cat diesel additive (which I use in all diesel engines anyway) or some other proprietary additive such as Lucas or Power Service Injection Pump Lubricant.
ULSD is very dry, that is, it has no lubricating qualities as far as the honed and close tolerance moving parts in the injection pump are concerned. Sulfur in diesel fuel lubricates the injection components so if the engine is of questionable manufacture (chi-com) or a pre-2000 engine, it's advisable to use an additive, much like using tetra-ethyl lead additive in pre-1960's gasoline engines to mitigate exhaust valve seat erosion caused by the abscence of tetra-ethyl lead. Pre-1960's 4 stroke gasoline engines were made with no hardened valve seats because the lead coated the seat.
Red dye is added to diesel (which is all ULSD by the way) to denote the difference between road taxed diesel and off road (no road tax paid) diesel. The dye makes it easy for a Federal Inspector to ascertain if you are using off road diesel in a road based (and tax applicable) vehicle and enforce the law accordingly.
Generators and classified on road, just like ag machinery, they are eligible for off road diesel.
I would, because the genset will be used only ocassionally, add a bio-cide to prevent algae growth in the fuel, as well as a proprietary injection pump additive plus run a quality, API certified, multi-grade lubricating oil.
Bottom line, is you get what you pay for, whether it's a welder, tractor or generator and the least expensive may, or may not be the least expensive in the long haul. Standby gensets need to perform without problems in time of need because auxillary power is peace of mind.
My genset has a Perkins, Tier 3 engine and it wasn't cheap but then I don't worry about in not operating when I need it (with proper maintenance and additives) of course.
Most times if the price is 'too good to be true', it isn't.
