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Did not know FE and deposits where at odds.
Quote:
THE TRADEOFF
The juggling act additive package suppliers perform is particularly challenging in maximizing fuel economy improvements and deposit control. With the available additive chemistries, it appears that maximizing one of these factors can lead to problems in maximizing the other parameter.
Mazzamaro believes that the increase in GF-5 fuel economy requirements as compared to GF-4 can be accomplished with current GF-4 friction modifier additives. Use of other friction modifiers that might provide even better performance is discouraged because it can lead to inferior high-temperature deposit control.
He says, "Unfortunately, very little has changed in friction modifier technology between GF-4 and GF-5 as the Sequence VID fuel economy improvement (FEI) limits were set at a level which barely requires a statistically significant improvement over GF-4 oils, and this minor improvement could be achieved via formulation modifications other than from the friction modifier type."
Mazzamaro maintains that meeting the TEOST 33C deposit-control test makes it very difficult to prepare automotive lubricants that exhibit high levels of fuel economy. He explains, "Inclusion of the TEOST 33C test in GF-5 to protect against turbocharger deposits resulted in limiting the formulator's flexibility in formulating high fuel economy engine oils using molybdenum friction modifiers."
Figure 3 data supports Mazzamaro's contention. An industry consortium conducted testing on five engine oils containing two different additive package technologies that differ in composition by friction modifier level and type. As noted, Oil I prepared with a molybdenum additive exhibits the highest level of fuel economy improvement, according to the Sequence VID test but does not pass the TEOST 33C test.
Szemenyei agrees there is a tradeoff between fuel economy and engine deposits.
Did not know FE and deposits where at odds.
Quote:
THE TRADEOFF
The juggling act additive package suppliers perform is particularly challenging in maximizing fuel economy improvements and deposit control. With the available additive chemistries, it appears that maximizing one of these factors can lead to problems in maximizing the other parameter.
Mazzamaro believes that the increase in GF-5 fuel economy requirements as compared to GF-4 can be accomplished with current GF-4 friction modifier additives. Use of other friction modifiers that might provide even better performance is discouraged because it can lead to inferior high-temperature deposit control.
He says, "Unfortunately, very little has changed in friction modifier technology between GF-4 and GF-5 as the Sequence VID fuel economy improvement (FEI) limits were set at a level which barely requires a statistically significant improvement over GF-4 oils, and this minor improvement could be achieved via formulation modifications other than from the friction modifier type."
Mazzamaro maintains that meeting the TEOST 33C deposit-control test makes it very difficult to prepare automotive lubricants that exhibit high levels of fuel economy. He explains, "Inclusion of the TEOST 33C test in GF-5 to protect against turbocharger deposits resulted in limiting the formulator's flexibility in formulating high fuel economy engine oils using molybdenum friction modifiers."
Figure 3 data supports Mazzamaro's contention. An industry consortium conducted testing on five engine oils containing two different additive package technologies that differ in composition by friction modifier level and type. As noted, Oil I prepared with a molybdenum additive exhibits the highest level of fuel economy improvement, according to the Sequence VID test but does not pass the TEOST 33C test.
Szemenyei agrees there is a tradeoff between fuel economy and engine deposits.
