Castrol GTX High Mileage 15W-50 oil provides extra protection for engines with over 100,000 kilometres and are starting to show signs of wear. As an engine gets older gaskets become brittle, seals can deteriorate and oil can burn faster. Castrol GTX High Mileage helps extend engine life by providing superior protection against deposit build-up, increased seal performance and protection against oil burn off. Castrol GTX High Mileage is the perfect oil to help extend the life of your engine.Castrol GTX High Mileage 15W-50 is suitable for use in automotive petrol engines where the manufacturer recommends an API SN or earlier specification 15W-50 oil is used. To find the oil type and viscosity suggested for your vehicle; either add your vehicle to My Garage or check with your manufacturer, vehicle user manual, your local mechanic or head in-store and talk to one of our friendly team.