RI_RS4
Thread starter
1) Fuel dilution has many causes. You cannot say categorically that it is due to sloppy programming or rich mixture. With DI engines, fuel dilution is primarily due to the fundamental design of the combustion chamber's fuel distribution pattern, and the ring pack design. There is ample research and engine design data regarding this, and fuel dilution in GDI engines is a topic of serious research in the automotive industry. In our case, these are racing rings, thin and light, capable of an 8250 rpm red line, and the combustion chamber uses a tumble/swirl distribution. The engine was designed to also run in the lean-burn stratified mode, which is perfect for allowing any fuel dilute to cook off, and given us a 25 mpg 420 HP V8 engine. Unfortunately, stratified mode is disabled in the US market, because of the high sulfur content of our fuel, and our mileage is reduced to 21 mpg.
It is true that mixture richness plays a part. However, most mixture richness these days is required of engines, because of emissions standards. Manufacturers do not have much of a choice here. If you look at how the ECU fuel maps are derived for MED 9 ECUs, you'll find that the programming is far from sloppy. Some highly advanced testing and numerical optimization algorithms are used in the design of the ECU operating space. In addition, this engine is under full closed-loop lambda control at all times. I have looked at air/fuel ratios under all normal operating conditions, and they are quite reasonable.
2) Define "broken-in". I'd consider an engine with over 10K miles on it sufficiently broken in for the purposes of testing. Another way to define broken-in would be to track cylinder wall wear, until it reaches an asymptotic value. In our case, Aluminum and Silicon would be our indicators. However, Silicon is the more accurate indicator in this engine, since the rings ride on glass walls. Clearly, by 8K miles we have reached the asymptote.
As I mentioned earlier, I have plenty of other intermediate oil data, on my engine, and on other engines, that substantiate the dramatic decreases seen with the mystery oil.
Plenty of back-to-back runs were performed with Motul. Other owners have back-to-back runs with Amsoil Euro and Castrol Syntec, both 5W-40, that are consistent with what I have seen with my engine.
3) Yes, that would be Renewable Lubes French Fry oil, as I lovingly call it. However, it is a custom formulation with additives that only Terry and the formulator know about. I'm just a simple test mule.
It is true that mixture richness plays a part. However, most mixture richness these days is required of engines, because of emissions standards. Manufacturers do not have much of a choice here. If you look at how the ECU fuel maps are derived for MED 9 ECUs, you'll find that the programming is far from sloppy. Some highly advanced testing and numerical optimization algorithms are used in the design of the ECU operating space. In addition, this engine is under full closed-loop lambda control at all times. I have looked at air/fuel ratios under all normal operating conditions, and they are quite reasonable.
2) Define "broken-in". I'd consider an engine with over 10K miles on it sufficiently broken in for the purposes of testing. Another way to define broken-in would be to track cylinder wall wear, until it reaches an asymptotic value. In our case, Aluminum and Silicon would be our indicators. However, Silicon is the more accurate indicator in this engine, since the rings ride on glass walls. Clearly, by 8K miles we have reached the asymptote.
As I mentioned earlier, I have plenty of other intermediate oil data, on my engine, and on other engines, that substantiate the dramatic decreases seen with the mystery oil.
Plenty of back-to-back runs were performed with Motul. Other owners have back-to-back runs with Amsoil Euro and Castrol Syntec, both 5W-40, that are consistent with what I have seen with my engine.
3) Yes, that would be Renewable Lubes French Fry oil, as I lovingly call it. However, it is a custom formulation with additives that only Terry and the formulator know about. I'm just a simple test mule.