Oil formulations required for modern vehicles are very different from those needed for older vehicles.
Oils for modern engines are made to recent API specifications and specific ACEA and OEM parameters dealing with fuel efficiency, extended drain intervals and aftermarket exhaust treatment systems. They are not designed for older engine needs.
A classic car's engine can have very different characteristics with cork/graphite/rope seals, low pressure gear driven oil pumps, larger oil galleries with greater dependence on “splash” and “cling” lubrication, and are typically lower revving with larger machine clearances.
Such different engine designs demand totally different lubricants, and the Castrol Classic Oils range offers formulations for older vehicles that have been specially blended for the work they have to do.
Look to the next article where we will touch on 'additives': Detergents, Antioxidents & Pour Point Depressents which all require careful balancing as they can all have pros & cons.
