Hello all,
I attended the DEER (Directions in Engine-Efficiency and Emissions Research) Conference in Detroit, MI two weeks ago and listened to a fascinating presentation titled, "Low-Reactivity Lubricants for High Efficiency, Spark Ignited Engines" by Terry Alger at Southwest Research Institute.
He asserted that different oil base stocks have different reactivities and when they are present in the combustion chamber have an effect in spark-ignition engines like an effective octane number. He showed his experiments with different base stocks in specially blended lubes as well as retail off-the-shelf ones (but unfortunately did not name them). He showed that a substantial difference in knock-limited ignition timing advance can result simply with different oil base stocks, with ester-based oils being the best in this regard; Group III severely-hydrotreated oils being middle-of-the-pack but I don't remember exactly which fared worst, although PAO comes to mind. The implication here is that just oil selection can allow for running more knock-timing advance, and a modest but not insignificant fuel efficiency and performance improvement can result.
The 2011 paper has not yet been released to the public, but when it is, will be freely available by following the links from the DEER website.
So my question is whether there is a suitable oil out there I can buy that has a substantially ester-based composition without PAO that I can try in my Audi S4? I spoke with the author of the paper and exchanged correspondences; he would only let that the commercial ester-oil he tested was for an aviation application and he did not deny or confirm when I suggested Mobil Pegasus1.
I have generally run Mobil1 of different viscosities depending on season, and actually Diesel oils in my gasser S4 like Mobil1 TDT, Shell Rotella T6 and Castrol Syntec 5W-40.
Thanks
I attended the DEER (Directions in Engine-Efficiency and Emissions Research) Conference in Detroit, MI two weeks ago and listened to a fascinating presentation titled, "Low-Reactivity Lubricants for High Efficiency, Spark Ignited Engines" by Terry Alger at Southwest Research Institute.
He asserted that different oil base stocks have different reactivities and when they are present in the combustion chamber have an effect in spark-ignition engines like an effective octane number. He showed his experiments with different base stocks in specially blended lubes as well as retail off-the-shelf ones (but unfortunately did not name them). He showed that a substantial difference in knock-limited ignition timing advance can result simply with different oil base stocks, with ester-based oils being the best in this regard; Group III severely-hydrotreated oils being middle-of-the-pack but I don't remember exactly which fared worst, although PAO comes to mind. The implication here is that just oil selection can allow for running more knock-timing advance, and a modest but not insignificant fuel efficiency and performance improvement can result.
The 2011 paper has not yet been released to the public, but when it is, will be freely available by following the links from the DEER website.
So my question is whether there is a suitable oil out there I can buy that has a substantially ester-based composition without PAO that I can try in my Audi S4? I spoke with the author of the paper and exchanged correspondences; he would only let that the commercial ester-oil he tested was for an aviation application and he did not deny or confirm when I suggested Mobil Pegasus1.
I have generally run Mobil1 of different viscosities depending on season, and actually Diesel oils in my gasser S4 like Mobil1 TDT, Shell Rotella T6 and Castrol Syntec 5W-40.
Thanks