Opinion: Extending PMI, Oil Drain Intervals

This Opinion piece appears in the Feb. 17 print edition of Transport Topics. Click here to subscribe today.

By Michael Buck

President

MCB Fleet Management Consulting

As the trucking industry continues to recover from the recession, those responsible for fleet vehicles are looking wherever they can to save money. One possibility for increased profits and asset utilization would be to extend preventive maintenance inspection, oil drain and grease intervals.

Fortunately, the oil companies have invested a significant portion of their profits in research and development. But when freight levels drop, margins get as thin as hot oil and the need to cut expenses reaches the maintenance processes, mistakes happen — and the first blunder is usually to extend oil drain, grease and PMI intervals without increasing the quality of oil and lubricants.

The misconception is that grease is grease and oil is oil. They aren’t.

• Oil — Even with the oil rating and certification process in place to meet government emissions standards, there are significant differences in blend packages, which, in fact, have drastically improved in the past few years. Had they not improved, auto manufacturers wouldn’t have extended oil drains on cars and light-duty trucks to 7,500 miles from the longtime standard of 3,000 miles.

Oil’s primary purpose is lubrication, but it has several other functions, including detergent properties that remove contaminants to extend not only the oil’s life but the engine’s as well.

Oil also moves contaminants to the filter, another process that has been improved.

Finally, higher-quality fuel provides better combustion, allowing fewer contaminants into the oil.

What becomes obvious at this point is that the better the engine operates, the longer the oil can perform as designed. However, anytime an engine overheats for whatever reason, it is imperative to change the oil because extreme heat damages the blend package. As the oil drains, the technician should (1) check the magnetic drain plug for particles, (2) check the oil’s condition, looking at and feeling it for contaminants such as moisture, antifreeze and metal particles, and (3) check for a burnt odor or other unusual scents.

Follow those steps when pulling the dipstick, and remember to pull oil samples midway through draining for the most accurate reading. Finally, an on-site oil-analysis machine can be a cost-effective means of preventing catastrophic engine failure. 

• Grease — Oil plus a thickener equals grease. Oil’s major function in the recipe is lubrication, and the thickener absorbs shock. Does your duty cycle require lubricating the equipment between PMIs and oil drains, or can you hit the fifth wheel at the fuel island? Yes, they do make grease designed for fifth wheels in heavy drop-and-hook operations and yard hostlers. Insufficient grease on fifth wheels will cause premature wear on front tires, steering and suspension components. It must also be noted that kingpins and spring shackles (if designed to be lubricated) cannot be properly lubricated without elevating the unit to release the load on these components. 

• PMI — Preventive maintenance inspections reduce breakdowns, maintenance and labor costs and improve driver morale. Without PMIs, breakdown frequency will increase, and on-road repairs typically will be 66% higher than with accurately scheduled maintenance.

Technological advances have perpetuated the need for scheduled maintenance on turbos, diesel particulate filters, selective catalytic reduction, exhaust gas recirculation systems and associated componentry. Without an effective inspection process that zeros in on the inherent problems, the early signs of these component failures will be missed.

Here are some advantages of improved preventive maintenance inspections, oil and lubricants:

• Increased asset utilization, driver productivity and morale, and organizational profitability. 

• Reduced heat for decreased wear.

• Longer asset life cycles.

• Higher boiling points and lower freeze points.

• Reduced contamination getting by the rings during the combustion process.

• Thermal stability.

• Reduced hazardous wastes.

• Better combustion — except poor fuel quality.

• Greater corrosion prevention.

• Less wax buildup.

• Higher resistance to oxidation caused by high temperatures. 

• Every dollar saved goes straight to the profit line.

The final factor in the equation is the driver. It has been proved that an operator can have as much as a 35% effect on fuel economy, and that becomes a factor in the combustion process as well as maintenance cost.

For example, it’s a prescription for disaster to extend the drain interval on an asset operated by a “problem” driver who consistently demonstrates poor fuel economy on a properly operating unit, has a high breakdown frequency and is inept when it comes to a proper pre-trip inspection. However, this can be overcome with a maintenance system that encompasses variable PMI scheduling.

Yes, even with all these challenges, you can extend your drains and increase profitability using a step-by-step PMI, accurate data and properly scheduled maintenance intervals. The result will be greater asset utilization, driver morale and retention.

However, it must be coordinated through operations to move the commodity profitably.

Ours is a volatile industry, but a maintenance plan that proactively manages the assets is just as important as a business plan that manages variable costs.

MCB Fleet Management Consulting, based in St. Simons, Ga., offers fleet maintenance advice and guidance to private, public, corporate and government fleet operations.