All this has been changing though, and in ways we could not have imagined at one time.
Do you remember when passenger car oils began getting thinner? By the 1990s there were at least 16 0W-30 oils registered with the Society of Automotive Engineers (SAE) registry for upcoming oils, even though many were not yet in production.
It wasn't long before Lubes N Greases (LNG) was writing 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 past year George Gill wrote an LNG feature on thinning oil viscosities in the diesel market. The story was 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. 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 question 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
