Effects of Excessive Engine Idling

Engine idling is often unavoidable during day-to-day vehicle operation. Whether it’s sitting in traffic or waiting in the school parking lot, excessive idling creates engine wear without advancing the odometer.

The service life of a motor oil is described in miles; however, it is greatly affected by a vehicle’s operating conditions. This is why AMSOIL provides definitions for normal and severe service. Commercial and fleet vehicles are automatically included in the severe service category due to the nature of their operating conditions. Vehicles that frequently tow, haul and plow are obvious candidates for the category, but excessive idling is often overlooked.

The detrimental effects of high idle-times are numerous:

• Decreased fuel economy
• Incomplete fuel combustion, leading to fuel dilution and lowered oil viscosity, additive concentration and oil pressure – all of which increase the risk of wear
• Increased oil consumption
• Compromised injector tips, turbochargers and valve seats (diesel engines)

AMSOIL Signature Series Motor Oil represents the pinnacle of oil formulation, but all oils eventually lose their ability to provide proper lubrication and component protection. We recommend changing Signature Series Synthetic Motor Oil after 700-hours of operation in addition to the other established guidelines.

This graph illustrates the importance of tracking both mileage and idle-time. It shows the hours of engine operation, or idle-time, versus the miles driven during a drain interval. The colored lines represent average speeds of a vehicle in four different scenarios.

Following the orange line in the graph shows that the Las Vegas taxi accumulated approximately 10,000 miles (16,000 km) before reaching the 700-hour mark. It operated for the same amount of time as the New York City taxi, but traveled twice the miles. This is a clear example of how the hour limitation can significantly impact the number of miles achieved during a drain interval.

Signature Series Motor Oil counteracts some of the effects of prolonged idling by preventing deposits and resisting oil volatility (burn-off). Its unique synthetic formulation maximizes energy efficiency for optimum fuel economy.

It is vital to install a quality motor oil in your vehicle and maintain an accurate log of both mileage and hours of engine operation. Combining Signature Series Motor Oil with the appropriate drain interval will help prevent engine wear and costly repairs.