Fuchs Titan GT1 Pro C3 XTL 5W-30 5 Litre. Quantity (Litres): 5 Litres. The product may only be used in diesel engines when also low sulphur diesel fuel is being used. TITAN GT1 PRO C-3 SAE 5W-30 can also be applied in many vehicles of Asian manufacturers if the use of a C3 engine oil is specified.