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Types of Oils: How Well Do You Know Synthetic From Conventional?

Engine oil dipstick. Do you know the differences between synthetic and conventional oils? Test your knowledge.

Oil changes are a fact of life for any car owner, but with so many types of oils to choose from, it can be difficult to know which is the correct one to put in your engine. The three types of oils used in vehicles today are conventional, full synthetic and synthetic blend. Do you know how each differs from the other?

1. Unlike conventional oil, fully synthetic oil _______________.

a) has customized individual molecules

b) is refined

c) has a base source of crude oil

2. Although synthetic oil is often touted as the best option by manufacturers, conventional oil may be recommended over synthetic for ______.

a) gas engines

b) older engines

c) engines with turbochargers

3. One downside of synthetic oil is that it _______.Types of Oils

a) costs more

b) decreases fuel efficiency

c) must be changed every 3 to 5 months

4. All oil must be changed on a regular basis to maintain engine health, but different oils require different changing intervals. Conventional oil should be changed ________.

a) when the oil pressure light comes on

b) every 20,000 miles

c) following the vehicle manufacturer’s schedule

5. The right oil to use in a specific engine isn’t simply a matter of personal choice, and running an engine with the wrong type of oil has real consequences. Using the wrong type of oil may ________.

a) cause an engine to burn rich

b) void a warranty

c) require you to change coolant types

6. In an effort to formulate an oil that is the best of both worlds, synthetic blend oil was born and is widely used. Synthetic blend oil _______.

a) is something you can make at home by mixing the proper ratio of synthetic and conventional oil together

b) has molecules with more uniform shape than full synthetic oil for smoother flow

c) provides a better defense against oxidation than conventional oil

7. Once you choose a certain type of oil, you aren’t committed to it for life and may decide another type is better for you and your vehicle. If you want to switch from using synthetic oil to conventional, you must first _____.

a) complete an engine oil flush

b) prime your oil pump with conventional oil

c) consult your owner’s manual and warranty

8. The differences in oils are not immediately apparent, but their abilities to handle different environments and pressures is. Therefore, oil must be rated and clearly labeled for consumers. Oil is rated by ____.

a) viscosity

b) the international standards agency, OAFL

c) hue

9. All oil must contend with the reality that engines run very hot. The oil that provides the best protection at high temperatures is ____.

a) conventional

b) synthetic blend

c) full synthetic

10. Conversely, many vehicles operate in cold conditions, which has an effect on oils and the engines that need them. Fully synthetic oil protects engines in cold temperatures better because _____.

a) it is thicker than conventional oil

b) it flows more rapidly through the engine at startup

c) it has an insulating effect

Remember, whether it’s synthetic, conventional or a blend, it’s important that you change your oil and the oil filter according to manufacturer-recommended maintenance intervals. Your engine will thank you.

Answers: (1) a, (2) b, (3) a, (4) c, (5) b, (6) c, (7) c, (8) a, (9) c, (10) b

Check out all the engine products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on types of oils, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Images courtesy of Blair Lampe.


Blair Lampe View All

Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter.  In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.

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