By Greg Roche on

Today’s tip is how to save money. Specifically saving money through a program to reduce idling. Some amount of idling is part of life for a driver and the company. However, excessive idling costs money and causes wear and tear on equipment. Setting an idling goal of 20% or less is a good target to measure overall truck idling and evaluate individual behavior. There are three cost impacts of excessive idling: fuel consumption, maintenance frequency, and oil consumption.

Fuel Consumption

Idling consumes fuel which directly reduces overall fuel economy. The rate of fuel consumption while hauling a load is of course greater than idling, but excessive idling can cause a major hit. The greater the amount of idling, the bigger the impact on overall fuel economy. An idling truck is getting zero miles per gallon.

Maintenance Frequency

Engine maintenance intervals are based on operating hours on the engine, not miles travelled. Oil changes when using CES 20092 oil and spark plug replacements are every 1,000 hours of engine operating time. If 40% of the engine time is spent idling, the maintenance interval is still 1,000 hours. The oil must be changed and spark plugs replaced after only 600 hours of the engine doing work since 400 hours (40%) were spent idling. Reducing idling will stretch the time between maintenance service.

Oil Consumption

Idling can consume oil at a greater rate than when the engine is driving. This is due to spark ignited engines having a throttled air intake which creates a relatively high vacuum in the cylinders. Reducing idling can therefore reduce overall oil consumption.

Overfilling engine oil can also result in increased oil consumption. When the crankcase is overfilled with oil, the connecting rods can dip into oil pool, like an eggbeater. This causes foaming of the oil which will be captured by the closed crankcase ventilation system, with some oil vapor being introduced into the intake system/combustion chamber. It’s important to check the oil level cold or at least 15 minutes after the engine is shut down, on level ground. Only add oil if the level is below the “ADD” line on the dip stick, do not top off. The proper time to add oil is illustrated in the diagram below.

The bottom line is idling costs money. A management program that encourages reduced idling will help reduce costs, which go straight to the business bottom line. Cummins is able to help analyze your engine operation including idle time, drive time, power demand, and fuel consumption. For assistance conducting a review, please contact:

Justin Loyear
Cummins Westport Regional Sales Manager, Pacific Region
(559) 479-9277