This item is - Castrol 1925A Classic 20W50 Oil, 4.54 Liter. Manufacturer Castrol Limited. The formulations required for modern vehicles are very different from those needed for older vehicles. In older engines with traditionally high oil consumption, this can cause detonation and pinking.In older engines where the carbon has built up over a number of years detergents can have a scouring effect, causing the carbon to flake off, blocking up oil galleries and spray jets.
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