Vauxhall Astra H - 07 1.6 Oil light comes on on long runs - carmalade
Don't think so.You can only read live data pressure if the is a suitable device fitted on the engine to produce a variable signal . The oil pressure warning light is operated by a switch that is either on or off,usually around 1 Bar. As suggested ,the only accurate way is a separate mechanical gauge,screwed into the oil gallery.