AMSOIL 0W-20 Versus Mobil 1 0W-20Can Mobil 1 Advanced Fuel Economy 0W-20 Synthetic Motor Oil improve gas mileage? Let’s also analyze how this product compares to AMSOIL Signature Series Synthetic 0W-20 Motor Oil.

In recent months, you may have seen television commercials featuring Mobil 1 Advanced Fuel Economy 0W-20 Synthetic Motor Oil. Mobil advertisements make claims that this product can improve fuel mileage by up to 2.3%. While this claim sounds intriguing, when one delves into the fine print in Mobil’s literature, there are details that can’t be communicated during a 30 second television spot.

The fine print tells us that these fuel economy gains are achieved when switching from heavier viscosity motor oils to the lighter synthetic 0W-20. From mobil.com.

Helps improve fuel economy based on 0.2-2.3% potential fuel economy improvement obtained by switching from higher viscosity oils to a 0W-20 grade. Actual savings are dependent upon vehicle/engine type, outside temperature, driving conditions and your current engine oil viscosity.

Mobil doesn’t offer particulars about what exactly these “higher viscosity oils” may be. Could they be 5W-30, possibly heavier? Were the baseline engine oils conventional or synthetic? Switching from a lower quality conventional 5W-30, 10W-30 (or perhaps even 40-weight) motor oil to a synthetic 0W-20 is bound to provide gas mileage gains. So while we will not question the quality of their product, Mobil’s fuel economy improvement claims in this context are a tad dubious.

This leads to another question. Why would someone switch from a heavier viscosity motor oil to a 0W-20? If your car’s owner’s manual suggests 5W-30, do not switch to 0W-20 for minuscule fuel economy gains. If your car is designed for 5W-30 engine oil, stick with it for proper wear protection. However, if your car or truck calls for 5W-20 motor, 0W-20 can be an acceptable replacement. Do not expect fuel economy gains when switching from 5W-20 to a 0W-20. They are both 20-weight oils at operating temperature, so there are no frictional advantages. The 0W-20 may offer very modest cold weather flow improvements (in some cases). The best option is to simply use the viscosity suggested by your owner’s manual.

Comparing AMSOIL Signature Series 0W-20 With Mobil 1 0W-20

While we haven’t performed any scientific lab or field tests with these two products, as we show below, much can be learned from the numbers published by AMSOIL and Mobil. In past comparative lab testing, AMSOIL Signature Series Synthetic formulas have dominated Mobil 1’s best offerings.

Cold Pour Point

  • AMSOIL Signature Series 0W-20 -53°C
  • Mobil 1 Advanced Fuel Economy Synthetic 0W-20 -48°C

Using the ASTM D97 testing protocol, motor oil is cooled to the point where it starts to congeal. AMSOIL Signature Series Synthetic 0W-20 Motor Oil has a moderate edge over Mobil 1 Advanced Fuel Economy 0W-20 Synthetic Motor Oil when it comes to cold start protection.

Total Base Number

  • AMSOIL Signature Series 0W-20 12.6
  • Mobil 1 Advanced Fuel Economy Synthetic 0W-20 8.8

Total Base Number (TBN) is a critical spec that measures a motor oil’s capacity to neutralize acids. When analyzing motor oils, this is where the men are separated from the boys. The potent AMSOIL Signature Series 0W-20 formula has a TBN of 12.6, which is about a strong as they come in passenger car motor oils. Mobil 1 Advanced Fuel Economy 0W-20 has a rather tame TBN of just 8.8. In simple terms, AMSOIL Signature Series 0W-20 has a far greater reserve alkalinity and a superior ability to protect engine parts from acids and combustion by-products. This implies that AMSOIL has formulated their 0W-20 with a far stronger additive package than Mobil has with their 0W-20.

Oil Change Interval

AMSOIL Signature Series 0W-20- Up to 40,000 km (25,000 miles) or one year.
Mobil 1 Advanced Fuel Economy Synthetic 0W-20- Change at interval as suggested by owner’s manual.

When examining the drain intervals between these two products, it becomes apparent that TBN is not the only stark difference between the two. Mobil 1 Advanced Fuel Economy 0W-20 is not recommended for extended oil change intervals and this could be partially attributed to its low TBN. AMSOIL Signature Series 0W-20 can stay in service for up to or one year. For severe service use, AMSOIL 0W-20 can still go for 24,000 km (15,000 miles) or one year.

Even if you do not intend to employ extended periods between oil changes with the AMSOIL product, it is still nice to know that your engine oil is “overbuilt” enough to protect over long periods and big miles.

Cost of Mobil 1 0W-20 Versus AMSOIL Signature Series 0W-20

The suggested retail price of Mobil 1 Advanced Fuel Economy 0W-20 Synthetic Motor Oil is about 35% greater than AMSOIL Signature Series Synthetic 0W-20 Motor Oil when employing our wholesale programs and buying “by the case”. In most cases you can have AMSOIL’s best synthetic 0W-20 shipped to your door for less than you would pay for Mobil 0W-20 at major retail outlets.

Contact us for a wholesale price list using the form on this page or call us at 1-800-748-5781 for more details.