I used to drive for my job. I could easily log 2,500 – 3,000 miles in one month driving from one client to the next. It was around this time that I started really paying attention to auto maintenance expenses. One idea my longtime mechanic offered to help me save was to switch from using conventional motor oil to using synthetic oil. If you are curious about what the differences are between natural and synthetic oil and how making the switch can help you save, this post is just for you!

Conventional motor oil 

Natural or “conventional” motor oil has been the standard for vehicles for decades. Only beginning in the 1970s was synthetic oil even an option for passenger vehicles.

  • Source: Natural motor oil ("mineral oil") is derived from the petroleum in crude oil, a naturally occurring fossil fuel.
  • Oil change frequency: Every 3,000 miles or 90 days, whichever comes first.
  • Performance: Less durable and thickens noticeably quickly—can leave "sludge" in the engine over time.
  • Recyclable: Yes
  • Average Cost: $12.97 / 5 qt. (Walmart.com)

Synthetic motor oil

Certain newer models now require the use of synthetic motor oil. If your vehicle does not fall into this category, here are some additional reasons you might want to make the switch.

  • Source: Synthetic motor oil is derived from artificial chemical compounds.
  • Oil change frequency: Depending on the brand and your vehicle, every 7,500 – 15,000 miles (some brands can sustain up to 20,000 miles before a change is required).
  • Performance: Protects engine against wear and tear (especially in cold conditions), better performance in high heat conditions, thinner and longer lasting, creates fewer emissions to add to the greenhouse effect, better horsepower and torque, better gas mileage, can clean and lubricate the engine.
  • Recyclable: Yes
  • Average Cost: $22.66 / 5 qt. (Walmart.com)

What about motor oil blends?

Some newer motor oil comes in a hybrid form, as a blend of both natural and synthetic motor oil. However, these are mostly designed to power off-road or racing vehicles, or specialty vehicles like motorcycles and boats.

  • Source: Crude oil derivatives plus artificial chemical compounds.
  • Oil change frequency: Depends on the brand and the blend (typically, every 5,000 – 7,500 miles is the beginning frequency recommendation).
  • Performance: Delivers a middle-ground level of performance (somewhere between natural and synthetic results depending on the blend and brand).
  • Recyclable: Yes
  • Average Cost: Anywhere from $4.99 to $25.99 and up depending on blend and designated use. (Google Shopping)

Compare and decide: conventional vs. synthetic

While it’s always best to consult your owner's manual and your mechanic before making changes, these calculations can also help you determine the best choice of motor oil to help you save funds.

  • IRS mileage rate (2014): $0.56 / mile
  • Average annual mileage (DOT, ages 35-54): ~15,000 / vehicle
  • Avg. oil change price (conventional): $25 (service, filter change, 5 qt. oil, oil disposal fee)
  • Avg. oil change price (synthetic): $65 (service, filter change, 5 qt. oil, oil disposal fee)

Conventional oil

  • # Oil Changes / Year: 15,000 miles per year / every 3,000 miles = 5
  • Total cost / year: 5 x $25 = $125.00

Full synthetic oil

  • # Oil Changes / Year: 15,000 miles per year / every 10,000 miles = 1.5
  • Total cost / year: 1.5 * $65 = $97.50

Savings by switching to synthetic: $27.50 / year

How Switching to Synthetic Oil Can Help You Save on Auto Maintenance