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Car owner's fuel savings lost to costly synthetic oil changes

I read your article about oil change frequencies, comparing the "old-school" advice to change your conventional oil every 5,000 kilometres to the "new-school" approach that uses synthetic oil and maintenance monitoring systems to greatly extend oil life.

Mazda seems stuck in the old school. I have a 2013 Mazda3 with the SkyActiv 2.0 engine. It takes synthetic oil, but Mazda insists that Canadian owners change the oil every four months or 8,000 km to maintain the warranty. I don't drive a lot, and the car doesn't have a monitoring system. So my most recent synthetic oil change was done just past 3,000 km because I hit the four-month window.

By comparison, my previous car was a Honda Civic that took cheaper conventional oil. But its monitoring system adapted to my driving habits and signalled me to change the oil only half as often, about every eight months, and still maintain the warranty. With my new Mazda3, the more frequent changes and more expensive synthetic oil are costing me more than the money I'm saving due to its improved fuel economy, relative to the old Honda Civic. I don't expect you to have a magic solution to this, but thought I would point out this wasteful anomaly. – Michael in St. Catharines, Ont.

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There is no getting around the warranty issue. Mazda requires changes every four months or 8,000 kilometres so you must follow those requirement if you hope to keep the car under warranty.

The new SkyActiv engine operates at an extremely high compression ratio, which may be part of the reason for the conservative oil change intervals. It is also possible Mazda has little experience with this engine out here in the real world and is taking a cautious approach. Your concerns about the resultant operating costs are certainly valid.

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