<p>Castrol GTX 10W 40 4L is a reliable engine oil formulated for strong sludge protection and extended engine life in petrol and diesel cars requiring this viscosity grade. Featuring Advanced 3X Clean Technology, it helps clean existing sludge while preventing new buildup and provides advanced defense against heat, contaminants, and wear. For best results, use during regular oil changes as recommended by the vehicle manufacturer to keep the engine performing smoothly.</p>