July 9, 2026 BY
IN Auto Parts

Introduction

As technology advances and vehicles become increasingly sophisticated, it’s easy for customers to be lulled into a false sense of security when it comes to essential vehicle maintenance. Many Australians don’t realise that urban drive cycles, short trips and stop-start driving can drastically reduce engine oil service life.

Severe and abnormal drive cycles can reduce the recommended service interval

Regularly driving short trips (under 20km), stop-start driving (city traffic), towing and off-road conditions are often classified by vehicle manufacturers as severe or abnormal drive cycles. Under these conditions, standard engine oil drains may not apply.

How is the oil affected by a severe or abnormal drive cycle?

Combustion by-products such as combustion gases, water and unburnt fuel can enter the sump and contaminate the engine oil. This can be exacerbated by stop-start driving and periods of idling whilst in traffic. It can take up to 20 minutes of driving before the engine and the oil reach temperatures that can force these contaminants from the oil. When a vehicle is regularly driven for less than 20 minutes at a time, the engine does not get hot enough for long enough to force the contaminants out of the oil. This can result in an excessive buildup of contaminants in the oil.

Unburnt fuel contamination lowers the oil’s viscosity and promotes oxidation, which by extension accelerates corrosion. Increased water concentration will result in premature depletion of the oil’s additive package. This leaves the oil more susceptible to acids which are formed by water and combustion by-products. Higher levels of water contamination contribute to low temperature sludge formation.

A major function of an oil’s additive package is to reduce wear. This technology is generally temperature activated and may not be effective in low temperature operations. Engines which frequently operate under low temperature regimes are more likely to experience accelerated wear, in particular valve train wear. Castrol Magnatec engine oils have been specially developed with ‘clinging molecules’ that provide protection against wear during the warmup period, activating quicker than traditional anti-wear additives.

Using quality parts and lubricants such as Castrol Lubricants, fitted by a quality workshop can contribute to extended engine.

Severe and abnormal drive cycles also impact modern diesel engines

Diesel engines with Diesel Particulate Filter (DPF) systems often struggle under certain conditions, such as stop start driving, to reach the temperature required to passively regenerate the DPF.

Under these conditions the engine management system is forced to actively regenerate the DPF by increasing the exhaust temperature, which is often assisted by an injection of fuel. Multiple active regenerations can therefore lead to increased fuel dilution and a lowering of the oil viscosity.

The drain interval recommended by manufacturers should be seen as a maximum rather than a minimum number

The service sticker placed on a vehicle in the workshop indicates when the next service is due. This will generally display two criteria, the kilometre figure and time indicator, to define the service interval.

Vehicles are due for service at whichever condition is reached first.

It’s not just about your engine oil!

A vehicle which only travels short distances each day or experiences high idle time will take longer to reach the ‘standard’ service interval. It is not uncommon for some vehicles to take several years to reach 15,000km. When vehicles are in the workshop, it’s not just the oil which is checked. Critical systems in your vehicle, such as brakes, shock absorbers and tires, are also at risk when not maintained at regular service intervals.

Servicing your vehicle more frequently will minimize the impact of severe or abnormal drive cycles. It will also offer your workshop the opportunity to ensure your vehicle is in the safest operating condition for you and your family.

How to communicate the importance of regular service intervals to your customers: regular and timely oil changes can extend engine life

Today’s engines, if properly maintained, can achieve up to 500,000km without major overhauls. This is more than twice the distance that can be travelled when compared to a poorly maintained vehicle.

To protect your investment, take the time to check your vehicle’s manual or talk to your service adviser to identify what your typical drive cycle is and how this may affect your oil – even between regular service periods. By doing this, you will maximize the life of your engine and keep your vehicle in safe operating condition. It will also minimize vehicle pollution and help to avoid potential car repair fees.