Amazon has 5-Qt Castrol GTX Full Synthetic 0W-20 Motor Oil for $21.56 – 5% when you check out via Subscribe & Save = $20.48. Shipping is free w/ Prime or on $35+ orders.

• Superior wear protection on critical engine parts
• 6X better wear protection than industry standards, as measured in the latest Sequence IVA test
• Superior sludge cleaning and protection against new formation
• 1.3X better sludge protection than industry standards, as measured in Sequence VH sludge test vs. API SP limits
• Full synthetic formula provides thermal and oxidation stability