Astron Energy (Pty) Ltd, licensee of Caltex-brand lubricants have introduced Delo 400 SLK SAE 15W-40 engine oil, a new top premium heavy-duty diesel engine oil. The new Delo 400 SLK with ISOSYN Advanced Technology improves on the Delo 400 MGX AND now takes top spot in the premium heavy-duty diesel engine lubricant range.

Delo 400 SLK SAE 15W-40

The new Delo 400 SLK SAE 15W-40 is a ‘low SAPS’, API CK-4 specification engine oil and is suitable for use with diesel fuel having sulphur content of up to 500ppm. The API CK-4 category of the new Delo 400 SLK remains compatible with older CJ-4 (of the Delo 400 MGX), CI-4 Plus, CI-4 (standard), and CH-4 categories.

Delo 400 SLK SAE 15W-40 offers improved oxidation stability allowing engines to have extended drain intervals, enabling smoother and undisrupted operations even for vehicles operating under stop-and-go and sever operating conditions. The new Delo 400 SLK’s exceptional anti-wear system also offers robust wear and corrosion protection of engine components. These all mean improved equipment reliability, reduced vehicle downtime and less operational costs.

Delo 400 SLK SAE 15W-40 has been field tested and in one such field trial, the trucks field tested reached an extended drain interval of 60,000 to 80,000km, attesting to the product’s enhanced oxidation stability and wear protection.

The Delo 400 SLK is able to boost the performance of various engine designs, allowing one oil for vehicles from different OEMs, from American to Japanese to European – new or old – with or without DPF after treatment device, thus helping to reduce inventory costs for vehicle operators. This is attributed the Delo 400 SLK’s compliance with lubricant standards for newer Euro IV and V compliant engines while remaining compatible with older engines.


Minimized operating costs

Exceptional soot dispersancy keeps soot in suspension, minimizing filter plugging, cylinder head sludge, abrasive polishing wear and oil thickening. Robust wear and corrosion protection of engine components due to effective antiwear additive system. Improves equipment durability and reliability while reducing equipment downtime.

Maintain emission control system performance

This new product has been formulated with the latest generation “low-SAPS” (sulfated ash, phosphorus and sulphur) technology containing reduced levels of metals, phosphorus and sulphur. Additionally, Delo 400 SLK maximises the life of sensitive catalyst metals and the cleaning intervals of diesel particulate filters.

Reduces inventory costs

Delo 400 SLK is a balanced formulation that provides excellent overall performance in mixed fleets of different engine designs, including modern low-emission diesel engines. This allows one oil for many services and reduces the chance of product misapplication. Additionally, the new heavy-duty oil is backward compatible with previous API Oil Service Categories and engine models.

Delo FleetPro SAE 15W-40

Astron Energy has also introduced Delo FleetPro SAE 15W-40 to the product mix. This introduction supports the new regulations relating to the minimum requirements of the approved standards for lubricating oils for internal combustion engines which means that in some SADEC countries, the sale of service categories of API CG-4, CF-4 and CF are no longer approved.

Delo FleetPRO SAE 15W-40 which is API CH-4 licensed will replace the current Delo Silver Multigrade SAE 15W-40 and the Delo Silver SAE 40 products, which were API CF specifications. This upgrade involves not only moving from API CF (1994) to API CH-4 (1998) but also moving from a monograde to a multigrade engine oil.

Multigrade engine oils are specifically formulated for longer engine durability and extended oil drain interval; this new generation of multigrade diesel engine oil provides better pumpability and lower wear & tear inside the engine.


Maintains engine life 

High-efficiency dispersant combination plus a proven metallo-organic anti-wear additive system provides excellent protection against the wear of critically loaded components under all operating conditions. Multigrade viscosity provides additional protection against wear at start-up and under high-temperature operating conditions. 

Preserves full power and performance 

Proven metallic detergent additive system preserves full power and performance by providing good upper-ring-belt deposit control under the high temperatures encountered in turbocharged diesel engines. 

Reduces maintenance costs 

Delo Fleet Pro features a state-of-the-art combination of high-performance base fluids and carefully balanced metallic detergent as well as ashless dispersant additive system. Service conditions, therefore, experience a considerable boost in cleanliness, making for safe and effective operations and the mitigation of downtime.

Maintains oil and filter service intervals 

The highly-effective antioxidant system inhibits the formation of sludge-forming materials. These substances have been known to lead to premature oil thickening and filter plugging. Delo FleetPRO’s high degree of soot dispersancy maintains oil drain intervals in modern engine designs. Additionally, the new formula offers an effective dispersant system that further assists production by keeping insoluble contaminants finely suspended in the oil. This minimises the chance of blocked filters.

​Get to know Delo FleetPRO SAE 15W-40 by speaking to one of Astron Energy’s account managers or distributor partners –

Save costs while fuelling productivity with Astron Energy and Delo.

To learn more about the Caltex Delo 400 SLK SAE 15W 40 and Delo FleetPro SAE 15w40, speak to one of Astron Energy’s technical experts, account managers or distributor partners – or

It could just be what your business needs to save costs while still being productive.