Oil that’s too thick can cause precious seconds to pass when little-to-no oil is available to lubricate parts, resulting in wear. It’s especially important in sub-zero weather when oil naturally thickens. Automotive Lubricants remain more fluid in cold weather for better protection than their conventional counterparts. Understand, too, that cold-weather protection is important regardless of your climate.
We assume only folks living in the frigid north need to worry about cold-weather protection. But “cold” to your engine is anything below operating temperature, even if it’s 80°F (27°C) outside. When you start your car in the morning after it’s sat overnight, the oil should flow as quickly as possible since most engine wear occurs during cold starts.
The primary differences are their viscosities when cold and once your engine has reached operating temperature. Let’s look at 5W-20 vs. 5W-30 first. The primary difference is their viscosity once your engine has reached operating temperature. Notice the different numbers in the viscosity ratings: “5W” and either “20” or “30”. The first number (5W) refers to the oil’s viscosity when cold, measured at 40°C. Technolube provides you the best automotive lubricants that will grow your engine performance.
It helps to think of the “W” as standing for “winter.” Lower numbers mean the oil will remain more fluid and easier to circulate throughout your engine for improved start-up protection. That being the case, when comparing 5W-20 or 5W-30 vs. 10W-30, the 5W oils will flow faster in cold weather, as indicated by their lower 5W rating.
This means the oil will flow more readily to lubricate the cam lobes, piston rings, cylinders, bearings and other vital components at startup. The sooner the oil reaches these components, the sooner it can protect against wear.
So, to summarize, when looking at 5W-20 vs. 5W-30, both will provide the same viscosity during cold starts. But they will remain more fluid and flow faster in the cold compared to 10W-30. The story changes once your engine reaches operating temperature. To determine the second number in the viscosity rating, the oil is tested at 100°C, which approximates normal operating temperature for most engines. The higher the number, the greater the oil’s resistance to flow and the higher its viscosity.
Automotive Oil with a higher viscosity at operating temperature provides a thicker lubricating film, which can help improve wear protection. But thicker isn’t always better; oil that’s too thick can result in oil starvation.
However, oil with a lower viscosity at operating temperature reduces internal friction, which maximizes fuel economy. Ultimately, choosing the right viscosity is a balancing act between competing priorities.
