hello everyone , i power washed my moggy a month ago,kept it in the garage today i wire brushed all the mud off and i painted hameroite underseal with added wax oil on the wheel arches ,then i sprayed the rest of the underneath of the car with engine oil will this help .
Old engine oil was the method used to prevent rust for many years and does really help (a good example is the mini subframe, front generally survived as it was covered in the oil from its leaky engine. The rear subframe on the other hand had no oil protection and would rust out). HOWEVER pretty sure using old engine oil as a underseal is now considered to be a serious health hazzard as it contains Carcinogenics. May be wrong about this but sure there are people on site who can put me right.
the problem with engine oil is that it gets washed off quickly and then you have no protection.. it protects the mini subframe because the oil is continually being replaced from the engine / gearbox