ah yes, interesting point as I am using an oil designed to last 3 to 4 times longer than manufacturer specified
Some oil is capable of it. The inherant problem is as oil gains contaminants it loses some of its lubricative qualities.
PM Lubes (in Australia) have a monitoring program whereby they monitor the contaminant level and effectiveness of the oil regularly. So even though it is designed to last 3 to 4 times longer, you MUST have it monitored, mainly for impurities but also signs the oil is breaking down.
My problem is this- regular monitoring can tell you if contaminant levels are too high, for example if your air filter is too blocked, or if there is an air leak past the air filter, or even if there is too much fuel in the oil from missing or running rich. The problem with a manufacturer specifying twice the distance on the same oil without monitoring it is that if you have a high silica (dust) level, your motor will die a horrible, premature death. The idea is to ensure contaminant levels are low enough as to not cause wear while the oil is in there for longer.
PM's oil will do up to 40 000 kilometres (lotsa miles) but will not reccommend it unless the free monitoring is carried out.
