Did You Know? About Viscosity Choices

As an oil company, we are frequently asked whether vehicles can use a different viscosity oil than what the manufacturer recommends?  Although this question is asked by operators wishing to gain benefits of lower viscosity oils, it comes up predominantly among the enthusiast or racing performance crowd, who are looking for a high-performance product for their modified engine.

The short answer to the question is: it depends.


First, it is important to know what the viscosity numbers mean. Here is a recap:


“W” stands for “Winter,” or the rating for external temperatures.

A lower number indicates better fluidity at lower temperatures.

A “0W” oil has the least resistance at startup and cold temperatures.

Viscosity graphic


This number indicates oil’s viscosity at high internal temperatures, when the engine is running.

Higher numbers indicate “thicker” oils at 100ºC / 212ºF.

Most modern engines in the past 20 or so years use a 5W or 0W oil, and this first number is fairly interchangeable, which means that either can work in your engine. Although you can pay a fuel economy price if using a 5W instead of a 0W, you can easily replace a 5W oil with a 0W without sacrificing protection in that a 0W oil offers instant operating viscosity and protection because it does not have to warm up to be efficient.

The second number tells us the viscosity at high temperatures and generally a higher number is better, especially where performance is concerned. ENEOS Motor Oil is proven to resist thermal breakdown and offer the ultimate protection in the most hostile conditions.


On a side note, ENEOS has been working in conjunction with Asian OEMs for nearly two decades to develop engine and transmission oils that operate with advanced protection, even at very low viscosities such as 0W-16 and 0W-8. These oils, however, are designed for excellent economy and not extreme performance scenarios.


To sum it up, it is perfectly acceptable to use ENEOS 0W-50 Racing Series oil in place of 0W-20 or 5W-30 and still guarantee protection of your engine.  ENEOS has racing partners that use our 0W-50 Racing Series oil in engines while producing 1000+ HP for some of the world’s most intense racing conditions.

3902 300 Front RS 0w-50

[Part # 3902-300]