FUELS & LUBES INTERNATIONAL
Quarter Two 2015
52
Finally, Sinha discussed the
Chrysler Las Vegas Taxi Field Test.
“One of the things that the industry
looks for is some meaningful correla-
tion between the sequence tests and
real-world performance,” he said.
The taxi field test ran for 100,000
miles covering two summers, with
an 8,000-mile drain interval, using
the same engine as the lab tests in
a Dodge Charger. The two new
reference oils being developed for
the Chrysler test were used, and
performed within the guidelines for
oxidation/nitration as well as kine-
matic viscosity according to used oil
analysis. “We didn’t see any surprises
for viscosity or oxidation and nitra-
tion,” he said.
In the end, the test showed
repeatability and reproducibility, and
discriminated on PVIS andWPD. It
met all the criteria, including 0W-16
viability and long-term engine supply
and readiness. The 3,800 available
engines should last through 2022. The
test development team recommended
precisionmatrix testing to begin.
From an OEM
perspective
Angela Willis, who manages the
Fluids Engineering Group at GM,
also gave a presentation on the sec-
ond generation dexos1™ which fo-
cuses on fuel economy. GM’s second
generation dexos1™ specification,
she said, is meant as a “stepping
stone” and a “learning opportunity
to allow formulators time to develop
formulations for the upcoming
ILSAC GF-6 specification.” GM
launched the second generation of
its dexos1™ specification for gasoline
engines in December 2014.
While GM currently manu-
factures engines designed around
SAE xW-30 and xW-20 engine
oils, it recognizes that smaller-
displacement engines and ultra-low
viscosity grades, such as SAE xW-
16, are becoming more prominent.
Although GM doesn’t foresee the
immediate need for the xW-16
across its engine platform, it would
like the second-generation dexos1™
specification to “keep one step ahead
of future hardware design needs,”
Willis explained.
Like GF-6, the second-genera-
tion dexos1™ specification includes a
test for fuel economy. GM is the first
North American OEM, Willis said,
to include a chassis-dynamometer
test specifically for fuel economy,
adding that it is common practice for
European OEMs. The fuel economy
test addresses the fact that different
engines have different appetites in
terms of viscosity. This fuel economy
test only tests fresh oils, but the goal
is to include used oils in the future as
well, she said.
The industry regards turbo-
charged, direct injection, small-
displacement engines as part of the
fuel economy solution, but, as Willis
reminded the audience, they face
challenges when it comes to robust-
ness. Specifically, they struggle with
turbocharger deposits and LSPI,
so GM added a test for each to the
second-generation dexos1™, having
discovered that additive chemistry
plays a significant role in both. For
LSPI, the second-generation dexos1™
specification requires an oil to
perform at least three out of five con-
secutive runs with no pre-ignition
events, and no more than two peak
pressure events per run.
By testing for fuel economy, LSPI
and turbo deposits, GM tailored its
own specification to pre-empt the
demands that GF-6 will soon make
of engine oils. Because formula-
tors will have to meet all these
requirements as well as protect the
robustness of engines, Willis said,
“This new specification will be a
challenge.”
燃料经济性、排放系统兼容性和对发动
机的保护：这些需求是当前开发的新发动机
油规格背后的需求。三月份在新加坡召开
的2015年F+L周上，参会人员了解了新汽
油机油规格制定的最新进展。ILSAC GF-6
和通用汽车第二代dexos1™ 规格都包含了
之前所没有的内容。由于这个原因，GF-6
的第一张许可证发放日期已推迟到2018年1
月，并将在一年后强制使用。
丰田汽车研究和认证工程部高级主任工
程师Teri Kowalski预测，GF-6的行业精确
矩阵将从五月份开始，持续至少三个月。这
个精确矩阵将确定测试在不同的实验室和重
复实验中是否可重复，可复制。
开发的GF-6有两大类。GF-6A可以完
全向后兼容，而GF-6B专为低粘度发动机油
而开发。粘度等级低于SAE 0W-16的油品
需要获得汽车油品顾问组（AOAP）批准。
GF-6包括六项测试，其中四项用于
替代目前GF-5类别，两项是全新开发
的。AOAP还没有完全接受这些测试，这要
等到行业精确矩阵完成之后。
四项替代测试包括由通用汽车赞助的氧
化和沉积物测试（GMOD）及克莱斯勒氧
化和沉积物测试。这两项测试用于替代程序
IIIG测试，测试工况类似，但都不包括磨损
测试内容。AOAP还需要决定用这两个测试
中哪个来替代程序IIIG。很有可能两个都会
被采用。
福特赞助了程序VH油泥测试。该测试
汽油机油的新规格：最新进展和时间进度
作者
Alison Gaines
特邀专栏
Angela Willis
