JERSEY CITY, New Jersey – ILSAC GF-7, the next passenger car engine oil specification due to market in four months, will make engines significantly cleaner and provide another incremental step toward improved fuel economy, an industry insider said at a conference here this month.
The new spec also demonstrated industry’s lesson from the development of its predecessor, ILSAC GF-6, and determination that future upgrades should avoid overambition that could stretch out the timing of updates.
“GF-6 was a huge undertaking,” Calcut, who represents Afton on several industry committees involved in engine oil spec development, told the ICIS Pan American Base Oils and Lubricants Conference Dec. 5. He noted that it took 10 years to bring GF-6 to market, more than twice as long as originally intended. “We developed six new engine tests [for GF-6], which was a lot more than we’d ever done before. With GF-7, when we first started talking about what do we need next, we said one of the things is we don’t want to repeat that. We want to get back to our regular cadence of upgrades but not have them as big.
“The idea is to continue to make incremental steps and improvements in the quality and performance of our gasoline engine oils, but let’s try not to repeat GF-6 and take on too much.”
One result, then was that GF-7 includes no new engine tests. The closest to a new test is a new requirement to measure an oil’s ability to mitigate low-speed preignition as the oil ages. GF-6 already measured an oil’s ability to mitigate the phenomenon, which can severely damage engines, when fresh. GF-7 extends that parameter to aged oil by adding a step at the beginning of the Sequence IX test to simulate how an oil ages during engine operation.
Commercial marketing of GF-7 is scheduled to begin March 31, less than three years after automakers formally requested the spec in August of 2022. That’s significantly shorter than the average time taken to develop previous specs. As Calcut noted, the International Lubricant Standardization Advisory Committee and the American Petroleum Institute have now developed 11 gasoline engine oil standards in 50 years, for an average pace of every 4 ½ years.
GF-7 still achieves significant improvement, according to Calcut. The two areas of biggest improvement, he said, are prevention of oil deposits and fuel economy.
“We all know that fuel efficiency is important, but what I hear most when I talk to [original equipment manufacturers], and I’ll quote, their concern is deposits, deposits, deposits,” he said. Developers raised results that must be achieved on the Sequence IIIH test for piston deposits. Doing so raises the bar for expected oil cleanliness and oxidation stability, he added, “and translates to cleaner engines all the way around.”
The greater requirement for fuel economy contribution helps OEMs meet ratcheting U.S. government regulations of greenhouse gas emissions. Calcut also cited what he described as secondary achievements of GF-7: the extension of LSPI prevent across the drain interval; new limits on sulfated ash content in oil; and ability to prevent wear of timing belts.
Some engine oils that meet GF-7 are already available for purchase, but ILSAC’s licensing agreements do not permit marketers to promote them as meeting the new spec until commercial launch on March 31. After that date, marketers will still be permitted for a time to promote oils as meeting GF-6. The older spec will eventually be declared obsolete and marketers no longer allowed to display the GF-6 trademark. The timing for that typically ranges between three and 14 months after introduction of the successor specification, but the timing for GF-6 has yet to be decided.