Low/mid SAPS in GDI Turbo engine

[blacksuit]

Hello, I'm weighing the pros and cons of running Redline's lower SAPS Euro 5w30 in my '08 VW GTI(FSI engine), motivated by reports that SAPS are a major contributor to carbon deposits in GDI turbo engines. My concern in using a lower SAPS oil is in it's reduced additive pack and it's interaction with high sulfur, poor quality US gas.
To give a little background on my situation, for a few years I've been running RL 5w40 or 10w40 with oci's of 3-5k miles(I'm at 40k). Recently the engine has started eating alot more oil(2 qts in 3k miles this last run) and I'm reminded of the deposit issues this engine is famous for. My driving patterns are tough on oil with at least 80% of the time driving aggressively in the crowded streets of LA, while the other 20% is divided between freeway and hills/canyons "fun driving". My car is flashed/chipped, I wait to reach op temp before revving past 3k rpm and treat cooldown with the same care.
Thanks for any help.

 

[il_signore97]

There are some reports (one from Lubrizol, the additive company) that seem to suggest that a low-SAPS oil can reduce the build-up of deposits on valves over time. This is contrary to previous thoughts that NOACK and/or TEOST scores were of primary importance (don't get me wrong, they may still be important, but Lubrizol suggests that the primary importance is SAPS level).

eddyvw (or edyvw?) on this forum has been trying low-SAPS oiis in his 2.0L VW TSI engines for a while now, and seems happy with them. He has done several UOA's on various oils to alleviate his concern (like yours) regarding how well low-SAPS oils retain TBN when using fuel with higher sulphur and ethanol. However, since you are in Ca, you may have lower sulphur fuel than most of the other states, so that might be something that helps.

Also, at your OCI of 3-5k, I doubt that you'd have any issue using a low-SAPS oil, and in fact, you may find that even a low-SAPS oil can go the full 5k without issue. UOA's would be necessary to determine oil life in this case.

As a side note, there are low-SAPS oils that are actually VW 504/507 approved such as Mobil 1 ESP 5W30 available, just so you know. I'm not sure that you care about official approvals, but if you do, there are readily available options out there.

 

[blacksuit]

Thanks for the reply, il signore. Yes, i saw the Lubrizol report. I think I'll give it a go and just make sure to do a uoa at 3000 mi with both tbn and tan.

 

[wemay]

Hi blacksuit, welcome to Bitog.

Here's an interesting read...
Turbocharged Direct injection Is Engine Oil’s Next Big Hurdle:

http://gf-6.com/sites/default/files/Turb...ig%20Hurdle.pdf

 

[JetStar]

I'm running a low SAPS oil right now. UOA from last oil change at 5000 miles, based on it, next oil change will be at 7000.

http://www.bobistheoilguy.com/forums/ubb...Tec#Post3395110

 

[il_signore97]

Originally Posted By: wemay
Hi blacksuit, welcome to Bitog.

Here's an interesting read...
Turbocharged Direct injection Is Engine Oil’s Next Big Hurdle:

http://gf-6.com/sites/default/files/Turb...ig%20Hurdle.pdf



Interesting article... Thanks for posting!

 

[il_signore97]

Originally Posted By: JetStar
I'm running a low SAPS oil right now. UOA from last oil change at 5000 miles, based on it, next oil change will be at 7000.

http://www.bobistheoilguy.com/forums/ubb...Tec#Post3395110




To be fair, I'd consider that oil a borderline mid-SAPS product with a suphated ash of 0.8% when compared to a true low-SAPS product like M1 ESP 5W30 with an SA of 0.6%...

However, your UOA looked good all things considered, and TBN retention over 5k miles was great. I'd keep using it!

 

[wemay]

Any time, il_signore97

 

[wemay]

...aditionally, that article is one reason i'm using the Kendall 5w-40 in the Santa Fe Sport Turbo. It's an ACEA A3/B4 certified oil. But in all honesty, at a 5K mile OCI (warranty limit), i'm pretty sure most GrpIII syns with an ACEA A5 would be just fine.

http://www.phillips66lubricants.com/docu...Sw%20826309.pdf

 

[il_signore97]

Originally Posted By: wemay
...aditionally, that article is one reason i'm using the Kendall 5w-40 in the Santa Fe Sport Turbo. It's an ACEA A3/B4 certified oil. But in all honesty, at a 5K mile OCI (warranty limit), i'm pretty sure most GrpIII syns with an ACEA A5 would be just fine.

http://www.phillips66lubricants.com/docu...Sw%20826309.pdf



Looks like a pretty good oil on paper. I have no experience with Kendall products because most oils that you guys get are hardly available north of the border

 

[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?

 

[Greasymechtech]

There is a Euro 5w40 from Redline, and 5w40 ESP from Mobil.

I'd consider the above two before using a 5w30.

It's time for an intake cleaning and engine oil flush.

 

[il_signore97]

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%.

 

[wemay]

Originally Posted By: il_signore97

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

Especially if you want to keep everything warranty friendly

 

[il_signore97]

Originally Posted By: wemay
Originally Posted By: il_signore97

Or, you can change your oil more often

Especially if you want to keep everything warranty friendly

In your case, yes! But in all seriousness, given the conditions inside your turbo DI engine, a 5K oci isn't terrible. I mean, it's not as short as the old fashioned 3K oci's of yesterday

Unless you drive a lot...

 

[wemay]

Originally Posted By: il_signore97
Originally Posted By: wemay
Originally Posted By: il_signore97

Or, you can change your oil more often

Especially if you want to keep everything warranty friendly

In your case, yes! But in all seriousness, given the conditions inside your turbo DI engine, a 5K oci isn't terrible. I mean, it's not as short as the old fashioned 3K oci's of yesterday

Unless you drive a lot...

Very true.

 

[blacksuit]

Quote:
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.

Do you have links from papers which show(nevermind conclusively) that low SAPS SUBSTANTIALLY reduces carbon deposits in TGDI engines? All I've seen is 1 or 2 pp presentations by Lubrizol with alot of graphics and few words. It's difficult to avoid the fact that low SAPS were developed for diesels and their particulate filters, for solely environmental reasons. Now, perhaps these low SAPS oil do substantially reduce TGDI deposits but it would be a real coincidence considering they weren't developed for this purpose. This is why I'd be interested in seeing evidence, especially from sources that don't have a vested interest(I remember the "scientific" papers of the tobacco industry...).
As far as TBN, this is is big issue for me. My last UOA(RL 5w40) had a TBN of 1.1 after 4500 miles! My viscosity however was very good at 13.69@100, fuel % was solid for this engine at 1%, insolubles good at .2%. With TBN the only other worry was the low flashpoint at 355 degrees(all wear metals either good or excellent). So, if anyone needs help with TBN it's me.
I do agree about a thicker viscosity in these engines(my most commonly used oils have been RL 10w40 and 5w40) but from all that I have gathered, RL 5w30 is basically 5w40 without the vii's. It's a very heavy 30 weight oil with a HTHS of 3.7. Anyway, it can't hurt to give it a run.