Castrol Classic XXL 40 Monograde Classic Engine Oil SAE 40 Lubricant 1L 1 Litre. This high-quality monograde engine and gearbox oil is formulated with selected additives to control low-temperature varnish and is suitable for pre-1950 cars and pre-1970 motorcycles. We are dedicated to customer satisfaction with over 10 years of experience in the automotive business. We offer free expert advice, genuine UK stock, and a no-leak guarantee. We provide free UK Mainland Shipping on all listings and offer express shipping upgrades. We also have a 60-day returns policy.