SAE Congress - I reviewed articles from the SAE conferences on powertrain and fluid systems in Tampa, Fl of October 2004 and the Paris 2000 conference. See SAE SP-1894 and SP-1550. Here are some excepts: Application of a Biodegradable Lubricant in Two Flexible Fuel Vehicles, Jesper Schramm: Vegetable biodegradable oils were used showing good wear characteristics despite excessive thinning over time. (These may be next! Animal and plant oils have esters as in Red Line oils.) The SMAC, Under Pressure Oil Aeration Measurement System in Running Engines, Bregent et al: Oil aging, valve train and bearing problems and thermal problems occur with aeration. Below 110 C there is no problem but as one goes up the aeration ratio increases rapidly. (A cooler running engine from a thinner, faster flowing oil may lubricate better for this reason alone - aeration was a hot topic). Development of the Sequence IV A Valve Train Wear Lubrication Testart 1, Sagawa et al: Viscosity data reveals that the more viscous oil did not significantly alter the cam angle of minimum oil film thickness. Of greater importance is the finding that the higher viscosity oil continued to exhibit boundary layer lubrication. (Ergo thicker is not necessarily better). The effect of engine intake air humidity was significant so that tests are now done with specified humidity conditions. It was postulated that fuel dilution of oil would elevate cam wear. Fuel dilution of 4.5 percent did not effect wear. (This would have the effect of lowering the viscosity about 1 grade). The Effects of Crankcase Oil Viscosity on Engine Friction at Low Temperatures, Cockbill et al: By using lower viscosity oils there is less friction, improved cold weather starting, improved fuel economy, a savings of starting system components and less wear by increasing the rate of oil pressurization and flow in the upper oil galleries. aehaas
AEHass, what do you think of Castrol's TWS Motorsport 10w60 oil? It is required by BMW in my M5 and I have been using it in my BB512i as well...and have been quite pleased.
I am not answering for Ali but it seems that Castrol under pressure for not producing real synthetics has done it with this one with 100% synthetic basestocks instead of hydrocracked mineral and calling them synthetic.
I would guess the 10W-60 is a good oil if a 60 wt. was needed. I heard some information that a manufacturing defect led to problems with those BMW's and the later recommendation of using a 60 wt. oil was a Band-Aide. I do not remember the source. Unless there is a severe problem with an engine or severe wear already then there is little use for a 60 wt. oil in any engine on or off the track. aehaas
AEHaas, I after much investigation/ research am begining to see the value in lighter viscosity oils, but only in regards to true synthetic oils, as they offer better protection and oil flow than a heavier viscosity mineral oil.
