Castrol GTX High Mileage 20W-50
Castrol is a very popular choice for synthetic oils, being well-known for their good quality overall. Castrol GTX, a conventional oil, rates well and was developed to resist sludge and protect your engine. Their additive blend includes Castrol's TriShield technology, which attracts and traps particles that cause damage, preventing sludge from building up. This oil holds up for intervals of 3,000-5,000 miles, and is capable of helping to improve fuel economy. Although Castrol GTX has a reputation for being somewhat overpriced, it depends on your region.