Some believe that changing oil weight for summer or winter months is a part of proper maintenance. Old conventional oil formulations had only one viscosity, and oil would thin out as it was heated. In winter months this caused trouble because the oil would turn to molasses and the pumps couldn't lube the engine properly. To combat this, a lightweight oil such as 10-weight was used for cold weather, so it would flow, while heavier 30- or 40-weight oils were best in summer months to prevent the oil from breaking down in the heat. Though in the recent years, the problem has been solved with multiviscosity oil, an oil that flows better when cold, then thickens and protects better when it's hot.
That’s what has been preached to us over the years – 4,828 kms per oil change! Some experts strongly suggest you would waste your money if you follow this advice. It’s always a good idea to follow the recommendations of your owner’s manual. Most owners’ manuals specify six months and between 8,000 km, to 11,000 km per change, a little sooner if you drive under “severe conditions”. All bottled oils come with additive packages already included from the refinery. These additives help to neutralize the acids that build up during use and disperse harmful particles to keep them from scratching metal surfaces. Most of these additive packages are used up within the first 500 to 1,000 miles of use. Beyond that, it’s just a matter of how long you allow the acids and particles to accumulate in the oil before changing it. For all intents and purposes, there’s hardly any difference between your engine oil at 4,000 km and at 8,000km. So don’t waste time and money changing the oil after a few hundred kilometers. Just feel confident in sticking to your owner’s manual recommendations.
Use a high-quality filter to keep the oil cleaner longer and always try to use high-quality oil. Synthetic oil is recommended for longer engine life and better performance. Synthetics are really just natural oil refined to a much higher degree, with more complex additive packages for improving performance in both everyday and extreme conditions. Many sports cars come filled with synthetic to offer the best possible protection. But if you want to better protect your engine over the long term, especially against extreme abuse like towing or constant stop-and-go traffic, synthetic might be for you.
Although these could be bold claims, they might be worth considering when choosing oil, but we can't remember the last time an engine failed on conventional oil, so going synthetic when you don't have to may be a waste of money and an abuse of your car engine.