Why engine oils are the way we see them today

By: Tony Swiatek

SPONSORED CONTENT: FUCHS LUBRICANTS gives an insight into oil grade variations the industry experiences

Why engine oils are the way we see them today
Fuchs keeps it simple


Why are there so many unique heavy duty engine oil specifications?

Many years ago we had only a few options in the list of engine oils often with only a viscosity grade as the notable difference, such as 20W‐40, 20W‐50, 15W‐40 or SAE 40.

Now there are so many variations it can be difficult to make the correct choice. So what has changed?

As a very general rule the updates to specifications are usually driven by gains in wear protection, emission control, fuel saving and in some cases, all of these.

Most original equipment makers (OEMs) spend a great deal of time and effort in development which will give them a competitive edge.

As such, the work they do is rarely shared amongst their competitors. This may then lead to a requirement for a unique specification.

OEM’s may collaborate on some levels with their combined work in grades such as those listed under industry bodies such as API & ACEA. These specifications often form the backbone of their own unique requirements.

Step change

A key change in the industry which has still taken time to filter through was the addition of exhaust after treatment systems. This usually led to the need for what has become a generic term of ‘DPFfriendly’.

As an answer to the requirement to decrease poisonous gases from the combustion process, many OEM’s incorporated EGR (exhaust gas recirculation) and variable timing to reduce the burn temperature. This had the required result of reducing the amount of poisonous gases, but in turn increased the amount of soot production. The response was to fit a DPF (diesel particulate filter).

Some chemicals used in engine oil additives burn at a temperature far higher than the DPF reaches and can then accumulate, causing blockage. The answer was to impose restrictions on SAPS (Sulphated Ash, Phosphorous, Sulphur).

This gave rise to the term "Low SAPS".

Fuchs Lubricants heavy duty diesel oil range

Fuchs Lubricants offers an engine oil product range which has a tiered approach to cater for all these requirements. This allows the choice of one of the higher specification products to cover all the preceding requirements, or alternatively, to select only the ones needed.


API CJ‐4 / ACEA E9/E6 – these high quality products boast many OEM approvals, specifications and recommendations. These products are normally required by the latest generation of vehicles with even tighter SAPS limits. This said, it does not prevent their use in previous specifications. These products are often the lower viscosity, higher fuel saving products and for that reason alone should always be a consideration when choosing a product.

TITAN CARGO SAE 15W‐40 & SAE 10W‐30:

API CJ‐4 / ACEA E9 – has many OEM approvals, specifications and recommendations. With the API CJ‐4 came the step change to the "Low SAPS – DPF Friendly" technology. Although not merely the "next thing", it met the new standards, while remaining backward compatible to the previous types. This product is widely used as a means to achieve all heavy duty diesel engine oil requirements in one product.


API CI‐4 / ACEA E7 – has many OEM approvals, specifications and recommendations. The API CI‐4 is from the early 2000’s and was the next step after CH‐4. Although similar to the below two products it now has even better soot handling and wear control. This is still a common grade in many areas and remains popular within the FUCHS heavy duty engine oil product portfolio.


API CH‐4 / ACEA E7 – has many OEM approvals, specifications and recommendations. The API CH‐4 superseded the CG‐4 in the late 1990’s. It is backwards compatible to all previous specs, however would be considered suitable to many of the same applications as listed for the TITAN UNIVERSAL HD SAE 15W‐40. The advantage of using this product is that it absorbs more of the ‘sooty’ by‐products, leaving a cleaner engine internally.


API CG‐4 / ACEA A3/B3/B4 – has many OEM approvals, specifications and recommendations. The API CG‐4 is from around the mid 1990’s and as such this product is well suited to on-road vehicles of that era. It may still be found commonly in many off‐highway, construction and agricultural vehicles.

By checking your requirement against the specifications listed for each product, you are then able to make a selection to best suit your needs.

It should be pointed out that most engine oils take the simpler approach of utilising the higher specifications listed within the Titan Cargo and Cargo Maxx range to cover an entire fleet.

These are in the "Low SAPS" category that offers the correct product for the latest technology vehicles, while offering appropriate protection for earlier specification vehicles.

Likewise the OEM specifications within these products often supersede the earlier specifications.

Heavy -Duty -Transport -Group ---Cargo -Truck -Plus -(2)

Back to the original question

Why are there so many unique heavy duty engine oil specifications?

Each OEM has their own take on what works best in their equipment which may not fit other hardware.

Fuchs Lubricants keeps it simple and provide a suitable product to cover your heavy duty engine oil application.

For more information visit www.fuchs.com.au

Tony Swiatek is Senior Product Manager at Fuchs Lubricants.

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