Is oil dilution worse in Sport+ mode?

[Magnams]

Hey all,
So I was reading about oil dilution with fuel, and seems to me that the gurgle and pop tuning in sport+ mode would directly contribute to excess un-burned fuel making is way into the oil. I've been driving in sport mode only for 2 weeks and my subjective sniff test seems to detect less fuel smell on the dip stick. What do you guys think?

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[creaturemachine]

My god, do we have nothing better to do?

 

[Magnams]

My god, do we have nothing better to do?

Have you changed your own oil? When I did, it smelled like I was draining gasoline out of the oil pan. I have never experienced that before with prior vehicles.

If you think that oil dilution is not a significant problem then just say as much. I myself am unfamiliar with the potential repercussions. Some people say, no big deal at the levels seen on UOA, others say your oil viscosity and lubricating properties suffer.

If there are risks of increases engine wear from it, then I probably won't drive in sport+ engine settings 24/7 anymore.

 

[elh0102]

Forced induction will cause oil contamination more than NA. If the Sport + setting operates as I think, it should have no effect on oil contamination. The higher compression of driving under high boost is more likely to cause it. Also, the combustion properties of different gasoline will vary.

 

[Frenzal]

I've read short trips is really bad for oil dilution. If this is your case, might be better to replace oil a bit more often.

But the MM seems to take that into consideration.

 

[Magnams]

Makes sense that forced induction will push fuel down past the rings.

I heard that the gurgling and popping is a result of injecting excess fuel that would remain unburned and make it's way into the exhaust system to combust. Wouldn't this fuel also make it's way elsewhere?

Do you know when during the combustion/stroke cycle the excess fuel is being injected at?

 

[Magnams]

I've read short trips is really bad for oil dilution. If this is your case, might be better to replace oil a bit more often.

But the MM seems to take that into consideration.

I drive 30 miles to work, I'm not sure what is considered a short trip but I think I get the engine pretty hot on my commute. I also drive gently for ~5 min to warm up before getting on the throttle.

I'm gonna shoot for 3k to 5k oil change interval

 

[creaturemachine]

Have you changed your own oil?

Yes, drain fill and move on, in nearly every change in every car I've driven. Used oil stinks because it's done its job. If you think there are any actionable insights from two weeks of sniffing oil then you may be doing it too much.

 

[Magnams]

Yes, drain fill and move on, in nearly every change in every car I've driven. Used oil stinks because it's done its job. If you think there are any actionable insights from two weeks of sniffing oil then you may be doing it too much.

Thanks for your valuable contribution to the discussion ?

 

[jedi03]

Is throttle an fuel mapping different between the modes other than the pops/crackles?

 

[bvanlieu]

Dilution is a bi-product of DI engines, not the sport pop mode. Short trips in general are not great for oil life/extended drain intervals regardless of DI or not.

I do a lot of HWY miles, not a lot of short trips, and I have measured dilution after 5K with both of my UOA, not as bad as the L15, but still not something I want to run 10-12K OCIs on when I can just change it for the price of a sample kit.

There is not any formula of if you have diution of X, DANGER. The danger is over time *if* your dilution is bad enough, the oil can fall out of grade, and more important if HTHS dips too low *and* you run the car very hard, you could fall below MOFT which is the wear zone.

Few things have to happen.

So what to do?

1. Change oil more frequently.
2. Use a higher viscocity to account for a drop via dilution (euro rated 30 grades have a HTHS of 3.5 or higher as an example)

I personally see no reason for 10-12k OCI unless I was running something like HPL or Amsoil SS. Great products but I DIY and 0/30 ESP is < $30 for 5qt. The Type S use case is very different then my previous ar that had 7L of oil and cruised at 1800 RPM all day (335 Diesel, 10K-12K OCI)

 

[Victorofhavoc]

Do an oil analysis.

We can speculate on smell all day long, but without data no one knows anything.

My last analysis showed no unusual amounts of fuel in the oil.

 

[Two Step Performance]

Do an oil analysis.

We can speculate on smell all day long, but without data no one knows anything.

My last analysis showed no unusual amounts of fuel in the oil.

Agreed

But my more simple answer to the question in the title: "No."

 

[s219]

In the old days, we'd call this phenomena "making oil" because when it was serious enough to matter, your oil level would go up in a noticeable way. I have to think that if you're not noticing short term excess oil level on the dipstick, it's not a problem.

The pops and bangs are created by injecting fuel in an off-throttle over run situation and either retarding the timing or cutting the spark, so that the fuel ignites when it hits the end of the stroke cycle or upon entering the exhaust. I don't think it's any more fuel than under normal throttle, and I don't think it's any more likely to make it past the rings than under normal conditions. So it's unlikely to have anything to do with dilution or making oil.

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