Why changing your car oil more often than recommended could save money and the environment

A common question posed by drivers is regarding the frequency of oil changes in their cars. At first blush, the answer appears clear cut: "Change it in line with the car manufacturer's guidelines." But, this isn't always the best course of action for all vehicles.

In the recent years, car makers have been recommending longer intervals between oil changes compared to a decade ago. This seems rational as both car components and the lubricants designed for them have evolved from those used in yesteryears. So, can one save time and money by spacing out the oil changes?

Note that the manufacturer's recommendation on oil change frequency specified in the vehicle's manual is just a guide on the maximum suggested limit that one shouldn't overstep to maintain the car's warranty. This maximum limit, though, is established based on optimal, lab-tested operating conditions. Unfortunately, the real-life working conditions of most cars are dramatically different from these experimental conditions.

To illustrate this, let's compare driving 9,320 miles in city traffic and the same distance on long trips. The car's engine has to work harder while navigating city traffic than it does on longer runs, thereby affecting oil consumption. Thus, we should establish different schedules for oil changes based on these different driving scenarios.

Ewelina Wołoszyn from Ravenol Polska explains that "many manufacturers explicitly mention that in scenarios involving challenging conditions, like highway-driving at high speeds, idling in traffic congestions, or hauling a trailer, an accelerated oil change cycle is recommended".

Many modern cars come equipped with systems that monitor the car's usage and its impact on the oil condition. Based on the operating conditions, the onboard computer system can determine if the oil needs to be replaced and informs the driver about the need for a service. If the operating conditions were challenging, such a notification might show up on the onboard computer display well before the manufacturer's suggested interval. So, what's the recourse in such a scenario? Clearly, one should get the oil changed.

Unfortunately, systems that oversee oil quality and alert the driver when it's time for a service aren't standard in all cars. Conversely, the long oil change intervals suggested by manufacturers are far more common. In effect, many uninformed users ear-mark their service visits according to the manual, covering 18,640 miles under challenging conditions with the same oil. In the long run, this could lead to the deterioration of the car components that need proper lubrication.

Why do car manufacturers suggest such long intervals between oil changes? Why such vast distances when an oil change after every 18,640 miles might not necessarily benefit the engine? The rationale is straightforward — it's about environmental preservation and cost-effectiveness. Fewer oil changes translate into less environmental pollution, which pleases the European Union authorities, and it also keeps vehicle maintenance costs down.

Increasing the oil change interval from 9,320 miles to 18,640 miles implies fewer trips to the service. For individual car owners, this might not seem consequential but for fleet owners who consider the total cost of vehicle management, it could impact their choice of a specific car model.

If you wish to, can you change the oil more frequently? Absolutely, you can. If maintaining your car in top shape and keeping it on the road as long as possible matter to you, then shrinking the manufacturer-recommended oil change intervals could be a good idea. I have yet to come across an authorised service unwilling to implement this approach. Firstly, it means more income for them. Secondly, the vast majority of mechanics agree that changing the oil every 6,213-9,320 miles, as opposed to the typical 12,427-18,640 miles, is better for the engine and could help prevent larger expenses down the line.