Purpose and Specifications

GM 15W40 Mineral is a premium mineral engine oil engineered for naturally aspirated and turbocharged petrol and diesel engines. This oil is designed to reduce friction between moving engine parts, maintain optimal internal temperature, neutralize combustion acids, and prevent corrosion and oxidation.

What the 15W40 Grade Means:

• The 15 indicates the oil flows easily during cold engine starts in winter conditions
• The 40 indicates the oil maintains proper thickness and protection at normal operating temperatures (around 100°C)

Key Performance Features:

• High resistance to oxidation—keeps the oil stable and effective longer
• High detergent and dispersant properties—cleans engine deposits and keeps contaminants suspended
• Excellent wear protection—shields engine components under normal to moderate loads
• Low evaporation loss—reduces oil consumption between services
• Works with petrol, diesel, LPG, and E10 fuels

Specifications: ACEA A3/B3, API SN/CF certified. Suitable for mixed fleet vehicles, highway cruising, and normal operating conditions.

When to Use and Replace

Replacement Interval: Change oil every 5,000 km or 2 months, whichever comes first. Mineral oils break down faster than synthetic alternatives, so regular changes are essential for engine protection.

Best For:

• Older engine designs and naturally aspirated engines
• Vehicles operating in moderate climates
• Fleet vehicles and mixed-use applications
• Engines not requiring extreme cold-start performance

Operating Temperature Range: Performs reliably in normal temperature conditions. Not recommended for extreme cold climates where thinner oils (5W or 10W) would be more suitable.

Frequently Asked Questions

Q: How does 15W40 mineral oil compare to synthetic oils?
A: Mineral oil is more affordable but requires more frequent changes. Fully synthetic oils last longer and perform better in extreme temperatures, but cost significantly more. 15W40 mineral offers solid protection for standard driving at a budget-friendly price.

Q: Can I use 15W40 in my older diesel truck?
A: Yes. 15W40 is widely used in diesel engines, particularly in commercial fleets and heavy-duty applications. It provides adequate protection for highway cruising and normal loads. Check your vehicle's manual for the recommended grade.

Q: Why does my engine manual recommend 10W30 instead of 15W40?
A: The first number matters for cold starts. 10W flows more easily in freezing conditions than 15W. Always follow your manufacturer's recommendation—using the wrong grade can affect fuel economy and engine wear.