I have just fitted a Chinese ST 5 to a customers Lister ST1 genset and its awful both in build quality and the way it makes flourecsents flicker due to voltage drop when a load is applied, a similar set with 3.5 KW Brush alternator drops 2 volts with the same load.
My consumption trials are based on a 21 KW 400 volt 3 phase load using an AVR controlled 37KVA set currently driven by a 270 cu inch Perkins engine, this load has been powered by 5 other engine alternator combinations including a 50 KVA set with a 1000 cu inch engine run at 850 rpm, Running these sets 10 hours a day 6 days a week and measuring the fuel used has to be the best comparative test. Obviously if I wanted pure consumption figures then this information is readily available but as I am also seeking the best engine regarding its ability to run on alternative fuels without issues and with a reasonable lifespan then my requirements are a bit unusual.
Mark.