10W-40 Oils
Our 10W-40 engine oils. Your handbook gives the grade and specification your engine needs.
Diesel Gard 10W-40 CI-4
A premium-quality mineral diesel engine oil formulated to meet the demanding requirements of modern heavy-duty engines.
Diesel Gard 10W-40 MCM
A high-performance diesel engine oil formulated for commercial vehicles operating under severe conditions.
Diesel Gard 10W-40 VMB
A high-performance mineral engine oil designed specifically for diesel engines.
Hypergrade Plus 10W-40 SG
A high-quality semi-synthetic engine oil for petrol and diesel engines.
Hypergrade Plus 10W-40 SP
A semi-synthetic engine oil formulated using high-quality semi-synthetic base oils to provide complete protection for modern passenger cars.
What 10W-40 means
10W-40 is an SAE viscosity grade. The first number, followed by W for winter, shows how easily the oil flows when cold: the lower the number, the faster it reaches the engine at start-up. The second number shows how thick the oil stays at normal running temperature: the higher the number, the thicker the oil.
So a 10W-40 flows more easily from cold than a 15W-40, and is thinner when hot than a 10W-50.
Use a grade your car's manufacturer lists, with the specification it asks for as well: oils of the same grade can meet different specifications.
More in our guide to what the numbers on engine oil mean.