Change oil pump from engine - 1997 Lincoln Continental

Now the daewoo engine is a re engineered copy of the opel europe engine as used in the corsa and astra .Now in the original opel engine the oil pump drive is six sided and 1cm wide and will last the life of the engine ,but in the daewoo the drive is about 2mm wide and is just a circle with one flat ,now if the oil isnt changed on a regular the oil get full of the effects of combustion and goes thick and horrible when cold ,this puts a strain on the pumps drive but as oil warms up it becomes very thin .Now what happens if vehicle hasnt had an oil change for a few years ?' and the fresh oil hold its viscosity then 20 miles down the road the customer rings up complaining,well the pump drive rounds off resulting in no oil pressure and then the oil light comes on ,10 seconds and the big ends are shot ,Recomendation is to change the oil every 6000miles and oil filter every thrid oil change ,use the cheapest oil available i prefer a diesel detergent type oil but anything is better than no oil change,forget these so called long life oils and just change it on a regular basis.