Q My owner’s manual says I need an API (American Petroleum Institute) service rating SF engine oil. All I can find is SG. Is that okay ?
A Yes. The API service ratings proceed in alphabetical order, so SG is a higher standard than SF. Owner’s manuals typically say “use SF or higher oils”, for example. However, you shouldn’t put an SF oil into an engine that requires SG ― that could void your warranty and shorten your engine life.
Q What’s a multigrade?
A The grade of an engine oil describes its viscosity (ability to flow). At lower temperatures, oil thickens and doesn’t flow as easily ― like molasses in January. The lower the number, the more easily it will flow at low temperatures. Multigrades are oils that contain additives called viscosity index improvers, and so they offer a range of viscosities (e.g. 5W30). The lower the number in front of the “W”, the greater the oil’s ability to flow at low temperature. The number after the “W” indicates the oil’s viscosity rating at normal engine operating temperatures. The “W” in the grade stands for winter.
Q Do I need a different oil in summer?
A Your owner’s manual will tell you what grade of oil your car needs. Most newer cars use a 5W30 oil year round. Older cars may need a bit more viscosity to keep the protective film on the cylinder walls. You’ll probably need to use a 10W30 in the summer, switching to a 5W30 in winter for better starting and cold performance.
Q Should I change the oil filter every time I change the oil?
A Most owner’s manuals call for a filter change every second oil change. However, the filter collects all the sludge and dirt from the engine, and your clean oil will be running through a dirty filter after every second oil change. Canadians average 2.8 oil changes per year. The difference between changing the filter every time and every second time is not much more than $5 a year. Considering the importance of clean oil to your engine, it’s awfully cheap insurance to change the filter every time.
Q Can I mix different brands of engine oil?
A Yes, if you must. Because all oils are manufactured to API and SAE standards, you can mix different brands. Because every company has its own additives aimed at enhancing the oil’s performance in your engine, you should not make a habit of mixing them ― you’ll get the best performance by using the same oil. At a pinch, it’s better to add a litre of 5W30 to an engine running on 10W30 than to run with low oil, but it’s not a good idea to mix grades.
Q How often should I check my oil?
A Get to know your car. Some engines burn more oil than others, and you may have to add a litre of oil once or twice between oil changes. Others don’t burn much oil. Check it regularly, whenever you get gas or at least once a week. If you’ve been driving, give the oil a few minutes to settle back into the sump. Then pull the dipstick out, wipe it off, put it back in all the way, and.pull it out again. Read the level of the oil ― it should be between the lines marked “full” and “add”, or “max” and “min”, depending on your car.
