So gang wondering if there are any views on which oil to use for a rebuilt motor's running in period. I've heard from "any oil will do" to "use something designed for it" but which one!? This one for £27 Or £30 this one ... Or this £30 Or this at £36 Or just pour in the tin of Halfords 20w50 I already have knowing it's coming out again in 500 miles and really is it that different to the oils above!? Help!!!!!!