Managing fuel costs remain a focus for fleet owners and operators, and there is significant savings to be gained through the conversion to lower viscosity heavy-duty engine oils.

Barnaby Ngai  


There is a growing demand for increased fuel economy in the Heavy Duty Engine Oil (HDEO) market that is being driven by two main factors—environmental concerns (reduced emissions) and managing fuel costs. There is an increased awareness of the emissions impacts and overall sustainability concerns in the industry, with many countries projecting to start activities to reduce the rate of fossil fuel consumption for heavy-duty vehicles by 2015. In addition, fuel is one of the leading operating costs for heavy duty trucking fleets, accounting for 30 to 40 percent of total operating costs. Therefore, even small increases or decreases in fuel costs can have a significant impact on a fleet’s bottom line.


With fuel economy being pushed to the forefront, the Heavy Duty equipment industry is looking to a number of areas to reduce fuel consumption. Areas that have seen increased focus in recent years include vehicle aerodynamics, improved driver behavior, low friction tires and down-speeding for optimal engine revolutions per minute (rpm).


In North America, PC-11, part of the next proposed American Petroleum Institute (API) commercial engine oil performance category, will place a heavy focus on improving fuel economy. Having said that, there is no reason to wait to consider engine oil as part of an overall fuel economy strategy.


It is important that fleets consider both the fuel economy benefits and the engine protection as that remains key to maximizing uptime. Improving fuel economy while compromising engine protection that can lead to reduced engine life or increased downtime is not a good trade off.  The following are several tips to consider when switching to lower viscosity engine oils.


#1: Consult with Your OEM

When considering any engine oil viscosity grade change, your first move should always be to consult with your OEM. If your engine is under warranty, you want to confirm that the switch will not compromise your warranty. Even if you are not under warranty, your OEM has extensive experience with its engine models in various environments and with various engine oils.


#2: Seek Lubricant Expertise

Beyond your OEM, seek the insight of your lubricant supplier. These companies invest heavily over many years to test their lubricants under various conditions in multiple engine types, and can offer valuable expertise not only on oil recommendations, but also on overall lubrication programs and efficiencies.


#3: Understand the Potential Issues:

In some cases, a change in viscosity grade has been known to cause an issue with the oil pressure indicator. At low RPM, it is possible to trigger a low-pressure warning, which could power down an engine. OEMs will know which engines are likely to experience these issues and can help find a solution.


#4: Have a Plan

In particular, if you manage a fleet, you should have a transition plan. Based on input from the OEMs and your lubricant providers, target a representative group of trucks in your fleet and run a test trial with candidate lower viscosity oils. Find a group of trucks that represent the varying range of operating conditions you use to see where the greatest benefits are and if there are areas where a switch will make sense. Exclude engines that may not benefit or may not be good candidates for lower viscosity oils—specifically, older engine designs that may result in increased oil consumption or the potential for increased bearing wear.


Yielding Excellent Returns

Fuel economy is a major consideration for HDEOs and the mobile equipment industry as a whole. By combining effective driver habits, aerodynamics, speed management and other proven tactics, significant fuel economy gains can be achieved. With proper planning and a high performance engine oil that does not compromise engine protection for fuel economy, the switch to lower viscosity engine oils can help complete a robust fuel economy program that has the potential to yield excellent returns for fleets and drivers alike. Fuel-efficient oils are currently available in the marketplace and their associated benefits can be achieved without significant capital expense.


Barnaby Ngai is the Category Portfolio Manager, Transportation Oils for Petro-Canada Lubricants Inc. For more information, contact To read the rest of the tips to ensure a smooth transition to lower viscosity HDEOs, visit for the free downloadable white paper, Tips When Considering Shifting to Fuel Efficient Heavy Duty Engine Oils.


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