I'm not quite sure what you're trying to say, but both mechanical and chemical shear stability are important. Fuel dilution will cause chemical shear over time, beyond the viscosity change seen by mixing oil and fuel.
Double-Super-Secret 5W-40 Audi RS4 Racing Oil
- Thread starter RI_RS4
- Start date
- Status
I'm not quite sure what you're trying to say, but both mechanical and chemical shear stability are important. Fuel dilution will cause chemical shear over time, beyond the viscosity change seen by mixing oil and fuel.
""The key and newer idea you might be missing is the effect of aromatic damage to a certain molecules, and finding those chemistries that resist that damage better than the conventional formulating is currently aware of""
This I understand but is not my question on how you can stop an oil from thinning when mixed with a thinner (fuel).
What you are talking about is the effect of the aromatic (fuel) on oxidation and chemical stability of the formulated fluid. Not what i asked about unles you say that by stopping the Aromatics from reacting with the base lube oil then it will not thin? How can that be? reaction or not a thiner fluid will bring down the vis of the target oil no?
bruce
This I understand but is not my question on how you can stop an oil from thinning when mixed with a thinner (fuel).
What you are talking about is the effect of the aromatic (fuel) on oxidation and chemical stability of the formulated fluid. Not what i asked about unles you say that by stopping the Aromatics from reacting with the base lube oil then it will not thin? How can that be? reaction or not a thiner fluid will bring down the vis of the target oil no?
bruce
Well, those techniques are part of the secret sauce. I'm just the user. I'll I can say is that it works.
- Joined
- Sep 28, 2002
- Messages
- 39,798
Good stuff here. I hope that we can stay at a low simmer
Surely this experiment represents some decent amount of $$ ..and there's a natural defensive posture that's adopted when one is challenged on the sensibility of the investment. We need to keep that in mind here. Not every challenge is a confrontation.
Now what would be fun, in a Myth Busters kinda way, is to have a head to head (imagine marque lights flashing):
Bruceblend Almighty vs. RL the HOBO.
..but beyond all the this and that .. I think that finding any blender, large or small, to formulate for a given application with specific issues ..would be difficult. For a major account, already representing a substantial throughput, sure, but for a niche market with ROI being limited?? I'd tend to (almost) look at this as a joint venture in R&D. Could another "gun for hire" get the job done? Maybe ..but finding a gun for hire may be a bit difficult.
Like I said, good stuff here.
Now what would be fun, in a Myth Busters kinda way, is to have a head to head (imagine marque lights flashing):
Bruceblend Almighty vs. RL the HOBO.
..but beyond all the this and that .. I think that finding any blender, large or small, to formulate for a given application with specific issues ..would be difficult. For a major account, already representing a substantial throughput, sure, but for a niche market with ROI being limited?? I'd tend to (almost) look at this as a joint venture in R&D. Could another "gun for hire" get the job done? Maybe ..but finding a gun for hire may be a bit difficult.
Like I said, good stuff here.
Ah, I get your point, and what you are missing. As I understand, there are two components to shear due to fuel dilution.
1) Fuel dilutes the oil.
2) Fuel causes aromatic damage to the oil, causing it to further shear.
#1 is reversable, as long as the fuel can vaporize before chemical damage occurs to the oil. Whatever fuel is left, does cause viscosity shift. The goal is to minimize the average dilution level, and thereby the average viscosity shift.
#2, additonal shear due to fuel can be reduced by the oil formulation.
If we stop or slow down chemical shear rates, and we reduce the fuel infiltration rate, then the final dilution percentage will be reduced. If aromatic reactions between fuel and oil are reduced significantly, then after a high dilution event (racing, cold start, idling) that might raise dilution levels, it is possible for the oil to recover as fuel burns off under normal operation.
Last edited by a moderator:
I'm speaking chemically here and not discussing the simple effect of adding a thin fluid to a motor oil which of course has a thinning effect by itself. With that said...
I don't understand how aromatic (fuel) damage can thin an oil. Fuel increases the oxidation of oil which has a thickening effect. If I'm wrong on the direction of viscosity change due purely to chemical interactions of fuel and oil, it is because there is a reaction going on in addition to oxidation that is of opposite sign (thinning) and greater magnitude than oxidation. I'm unaware of that possible reaction.
I don't understand how aromatic (fuel) damage can thin an oil. Fuel increases the oxidation of oil which has a thickening effect. If I'm wrong on the direction of viscosity change due purely to chemical interactions of fuel and oil, it is because there is a reaction going on in addition to oxidation that is of opposite sign (thinning) and greater magnitude than oxidation. I'm unaware of that possible reaction.
JAG, that would be true for a straight weight oil. Think just a bit outside of the box.
""I don't understand how aromatic (fuel) damage can thin an oil. Fuel increases the oxidation of oil which has a thickening effect""
That is what I have always been taught about fuel dilution and that this effect is much stronger than "dilution" from just the thin vis of fuel alone. Should make NO difference in multi or straight wt.
bruce
That is what I have always been taught about fuel dilution and that this effect is much stronger than "dilution" from just the thin vis of fuel alone. Should make NO difference in multi or straight wt.
bruce
I think I get what you are saying. The aromatics break down the polymeric viscosity index improvers? Those pesky trouble-makers!
Yes, and European car manufacturers like to specify large viscosity ranges with high HTHS that are difficult to meet without gobs of VIIs. VW/Audi require minimum HTHS of 3.5. Unfortunately, they do not test for HTHS over the life of the oil in the engine, so it is easy for an oil formulator to game the testing to meet approval, yet have an oil that shears at the slightest sign of chemical attack.
Oh the shame of it all.
Oh the shame of it all.
Hmmm. I wonder what some of those nifty oil experiments might have been between 12K and 15K miles, as shown in the post that started this whole mess.
Add one more downside to polymeric VIIs. I started some threads in the PCMO forum about their negative effects on lubrication. I think they are a crutch used to "meet spec" and do it with less money.
Quote:
It sounds like current API rated oils for these cars are simply not good enough for these engines.
To me, it sounds like the current Audi-spec'd oils are simply not good enough for these engines. I don't think the API has anything to do with it. American engineering is what's getting the job done well!
This is a great thread.
Is it accurate to say then that what makes this oil so good is the 30% HOBS that is being used? Final blend obviously matters most, but I'm getting from this that much like many other esters used in with other various base oils, the HOBS is the "key" component? Hundreds of different esters exist and are used in many synthetics. It sounds like being this RLI is also a blend, what seperates it from the pack is the HOBS aspect of it?
Is it accurate to say then that what makes this oil so good is the 30% HOBS that is being used? Final blend obviously matters most, but I'm getting from this that much like many other esters used in with other various base oils, the HOBS is the "key" component? Hundreds of different esters exist and are used in many synthetics. It sounds like being this RLI is also a blend, what seperates it from the pack is the HOBS aspect of it?
Are there any results out there for other viscosities of the RLI Biosyn? Maybe in a 5w30 or 0w20? It seems that Terry has indicated the RLI oils work well in cars with fuel dilution issues, though I don't know if this is true for all of the different viscosities.
If I recall, Terry has done some personal testing with 0W-20 in his 06 Mistubishi Outlander and 10W-30 in his 302 V8 and loves the results in both.
BTW, all testing on BIOSYN by Terry has either been for himself or his customers like me. As far as I know, Terry has not performed consulting for Renewable Lubricants.
BTW, all testing on BIOSYN by Terry has either been for himself or his customers like me. As far as I know, Terry has not performed consulting for Renewable Lubricants.
I would give the Redline 5w-40 a try in your engine.
98, I appreciate the suggestion. 11 months ago I might have taken you up on it. In fact, Terry Dyson suggested Redline 5W-40 as one of the oils to try in my engine, before we had done any testing. But, since it was not Audi approved, I was reticent to use it.
Since that time, we have performed extensive oil testing on multiple RS4 engines. Terry understands quite well what the engine is doing to oils and how to engineer the oils to combat those issues. At the point that we had basic understanding, we went through a series of controlled experiments with my car as a test mule to confirm some of Terry's theories. At any point, Terry could have suggested that I use Redline. He did not.
Once the Terry's theories were confirmed by testing and by some research, I gave approval for him to either suggest or develop a no holds barred oil for the RS4 FSI V8. This took us to Renewable Lubricants, who had the leading edge chemistry and formulation capability necessary to develop Terry's oil ideas further.
Which brings us to this point 11 months later, and 10K miles into testing the BIOSYN 5W-40. Using this oil has dropped fuel dilution by better than 2:1, has increased oil life by 2 or 3:1, and has dropped iron wear rates by 3:1 or better. This has been confirmed in multiple engines. Now I've looked many UOA's on BITOG, and I've seen increase OCI's, but I've never seen such a dramatic decrease in wear rates as I have with this oil.
Happily, I'll stay with BIOSYN and will work with Terry to tweak the formula. After 10K miles on the initial 5W-40 blend, I am now running a test of some modified oil, which Terry believes will perform even better. We'll see!
- Status
Similar threads
