All this has been changing though, and in ways we couldn't imagine at one time.
I do remember when I first noticed passenger car oils getting thinner. When I saw the first 0W-30 I thought it interesting. Even more interesting, though, was when I looked at the Society of Automotive Engineers (SAE) registry for upcoming oils, there were actually 16 companies with a 0W oil registered, even though they were not yet in production.
I later saw an article in Lubes N Greases (LNG) about SAE 0W-16 and 0W-12 and 0W-8 oils that were coming and more recently the 0W-0 oils being tried in Japan.
This week, George Gill wrote an LNG feature on thinning oil viscosities in the diesel market. The story is titled Heavy-duty Shifts to Lighter Oils. In recent years, 15W-40 diesel oils began yielding market share to lower viscosity SAE 10W-30 oils.
Part of the reason is the fuel economy benefit that lighter oils offer. For over-the-road truckers, the cost of fuel alone is 30 to 40% of a trucking firm's overall costs. (I bet you didn't know that.) Another reason, according to the article, has to do with the new engine architecture with its tighter clearances, thus requiring thinner lubes that can flow more readily to engine components.
There's a third reason for the thinner oils. In colder temps these lower viscosity oils will decrease warm up times and provide better protection in colder climates.
You may be wondering, though, "Is my engine still protected?" The answer to that is that this has been going on for years now with millions of miles of data to support this move to lighter oils.
CK-4 and FA-4
The article turns to address the newer API categories of CK-4 and FA-4. CK-4 was designed to have backward compatibility built into it. This has resulted in wider acceptance of the new designation. FA-4 oils are not so versatile. FA-4 oils in modern contemporary engines, however, do offer a 1% fuel economy improvement, the article states.
Despite the benefits outlined for thinner oils, 15W-40 remains the category leader for heavy duty diesel engines, but 10W-30 is the fastest growing segment during these past 10 years.
READ THE FULL STORY HERE:
https://www.lubesngreases.com/lubereport-americas/heavy-duty-shifts-to-lighter-oils/
RELATED LINK
CK-4, FA-4? Still Confused About Diesel Engine Oil Specs?
Photo by Matthew T Rader on Unsplash
