Originally Posted By: blacksuit
Interesting. So, to summarize the article, the two key concerns for TGDI's are oxidation and volatility, the former being handled by antioxidants and detergents. The effects of fuel dilution are mitigated by anti-wear additives. Their prescription for TGDI's are robust additive pack + oxidatively stable base stocks.
Allright, now I'm not sure I want to use the "Euro" RL.
First off, it's not really a low SAPS anyway(.63% ash), so I'd be choosing an oil(w/ a reduced add pack) over the standard RL 5w30 simply because it's somewhat milder in the SAPS department. Not sure it's worthwhile.
Btw does anyone know the SAPS % of the standard RL?
I can't say that I fully agree with your assessment. The article was great, but we have to remember that it is a generalization and does not equally apply to every single engine oil product on the market. Oxidation is a good example. Perhaps a normal conventional oil may rely quite heavily on additives, whereas a top tier synthetic with high end basestocks will already have a naturally higher oxidation resistance. Therefore, it will rely less on additives for that purpose (although additives are still important in any finished oil). Volatility again varies with basestock quality. A top tier synthetic will have a lower volatility versus the same viscosity conventional oil.
All oils have anti-wear additives. The most important thing to remember when speaking about low-SAPS oils is that they have less ash-producing and/or phosphorus/sulphur-based additives (i.e. the ones that contribute to a higher SAPS value in the first place). The most common end result is an oil with a lower starting TBN, which means that the oil will not be able to neutralize acids for the same
length of time as a full-SAPS product. However, a lot of times the additives that are removed are somewhat replaced with higher cost, non-SAPS contributing additives.
In terms of fuel dilution, the easiest way to counter that is to increase the starting viscosity of your oil (i.e. from a 30 grade to a 40 grade) much like the German OEM's do. This ensures that you will have a safe minimum viscosity over a longer period of time. Or, you can change your oil more often
It seems that the benefits of low-SAPS products in DI engines may be worth any trade-offs if they do in fact greatly reduce internal deposits on valves, EGR systems, and particulate filters (as they begin to be legislated onto gasoline DI motors in the future if that ever goes through).
Also, I'm a proponent of a slightly thicker oil in DI motors because they tend to produce soot particles in a similar way to diesel engines (due to the nature of combustion). These do find their way into the oil and are highly abrasive (hence DI engines with abnormal wear on components such as timing chains, etc). A good additive package to deal with soot is important in these engines IMO.
Lastly, Redline's Euro oil at 0.63% is definitely low-SAPS. The way I see it, all of the low-SAPS offerings on the market are somewhere in the 0.5-0.7% range, the mid-SAPS are 0.8-0.9% range, and the full-SAPS generally have >0.9%. I'd imagine that the normal Redline has a SAPS value of over 1%.
