The recommended engine oil for a 1999 Ford Focus depends on the engine it has. The Focus was available with several different engines in 1999. You
must check your owner's manual to find the exact specifications. The manual will specify the correct viscosity (like 5W-30 or 10W-40) and the type of oil (conventional, synthetic blend, or full synthetic).
Without knowing the engine size, I cannot give you a definitive answer. Looking in your owner's manual is the only way to be certain.
