For various reasons my P reg 1.4 Corsa was very low on oil so I filled it from the container of engine oil my husband keeps in the garage. This apparently was wrong. He says that old fashioned 20/50 oil is not suitable for a modern relatively high performance engine like mine. Is he just trying to stop me using his supply of oil or is he serious? What damage if any is it likely to do to the engine? Will it do for a while or should I get it changed? T.