↑ “History of Castrol”. BP. BP. Bản gốc lưu trữ ngày 5 tháng 6 năm 2014. Truy cập ngày 15 tháng 6 năm 2014. Early in the new century, Wakefield took a personal interest in two sporty new motorised contraptions – the automobile and the aeroplane. The company started developing lubricants especially for these new engines, which needed oils that were runny enough to work from cold at start-up and thick enough to keep working at very high temperatures. [...] Wakefield researchers found that adding a measure of castor oil, a vegetable oil made from castor beans, did the trick nicely. They called the new product 'Castrol.'
