http://www.lubereport.com/e_article000317018.cfm?x=b11,0,w
"Why would two distinct GF-4 passenger car motor oils – which earlier had passed the rigorous Sequence VIB (“Six B”) engine test for fuel economy – repeatedly flunk the same test now? That's the mystery facing ASTM and its engine test stewards."
and
“The bad news is that it’s difficult to get a GF-4 product into the marketplace. The good news is that any GF-4 product that does reach the market will have the best available fuel economy performance and meet the needs of consumers.”
"Why would two distinct GF-4 passenger car motor oils – which earlier had passed the rigorous Sequence VIB (“Six B”) engine test for fuel economy – repeatedly flunk the same test now? That's the mystery facing ASTM and its engine test stewards."
and
“The bad news is that it’s difficult to get a GF-4 product into the marketplace. The good news is that any GF-4 product that does reach the market will have the best available fuel economy performance and meet the needs of consumers.”
