Castrol 06247 EDGE 5W-20 SPT Synthetic Motor Oil - 1 Quart Bottle by Castrol

I tried to make an informed purchase by looking at the different oil manufacture websites for a breakdown of what's in their products. However, all I got were buzzwords like "High Performance", "SynPower", "Full Synthetic", and for this product, "Edge with Syntec Powered Technology" And when I find their product data sheet, they labeled their additives as "proprietary." This kind of secrecy reminded me of how food companies used the word "spices" in their ingredient list.Then I read reviews from other car owners and all I got were anecdotal experiences, such as "my car is performing better" or "It's amazing. I believe 100% in this product!"Despite the lack of concrete information, I went ahead and purchased this product, and then I paid an oil analysis laboratory to get some hard facts. Not surprisingly, "Syntec" is no where to be found in the oil. To save you some Googling, I included a brief explanation in the additives break-down below (units are in ppm and the values in parentheses are universal averages for 5W-20 oils):Calcium [detergent/anti-corrosion]: 668 (1903)Magnesium [detergent/anti-corrosion]: 1413 (71)Phosphorus [anti-wear]: 705 (647)Zinc [anti-wear]: 818 (756)Molybdenum [anti-wear]: 72 (73)Boron [anti-wear]: 65 (82)The most interesting thing about Castrol Edge with Syntec is the reliance on magnesium as the main detergent/anti-corrosion agent. This is typically seen in oils designed for diesel vehicles. The other interesting thing to note is the above average zinc count. Zinc is known to degrade catalytic converter performance, and since I live in California, this is a problematic issue due to the state's strict emission regulations.The other important characteristic of engine oils is Total Base Number (TBN). This value indicates the amount of anti-corrosion (acid neutralizers) additives are in the oil. It is an important indicator of the service life of the oil. The TBN for my unused oil sample is 10.7, which is above average. It is important to note that TBN does not decline at a constant rate, and the rate of decline is different for each oil type and rating, as well as driving habits and conditions. With this is mind, I went ahead and performed an used engine oil analysis at 8,510 miles and the sample came back with a TBN of 4.0. Oil change is usually recommended when the value is 3 or less. The lab recommended that I can shoot for an oil change at 10,500 miles. I'll post an analysis of that oil change when the car reaches that threshold.Last, but not least, is the physical characteristics of the oil. And this is where the synthetic nature of this oil gives it an advantage over conventional oils. Synthetic oils maintain their viscosity ratings longer and more consistently than conventional oils. My unused oil measured 8.50 centistokes (cSt) at 100°C and it was reduced to 8.41 cSt after 8,510 miles. Both values were well within the viscosity rating of 20.In conclusion, based on the oil analysis and the performance of my engine with this oil, I give Castrol Edge with Syntec 4 stars. It will get another star if my next oil change at around 10,500 miles shows good results. I hope my review provided you some of the data you need to make an informed purchase. Please remember that my review is based on two samples and a lot more are needed to make a conclusive observation.**Update: 7/30/2014**The lab result for the oil change done at 10,500 miles shows really good results. In fact, the TBN is higher (at 5.5) Because of this, it is recommended that I can shoot for an oil change at 12,000 miles.**Update: 4/26/2015**Looks like the marketing department is at it again. They figured that they could drop the byline, "with Syntec Powered Technology" and just call it "Edge" (¬_¬)

Fast

great oil