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14:7 is the theoretical (stoic) optimal a/f ratio. It will rarely, if ever, be achieved. Adding more fuel allows the manufacturer to recommend 87 octane while reducing knock, and protecting the engine, at the expense of fuel mileage (and apparently oil dilution in extreme cases.)

Example of a fuel map
View attachment 441608
As it was just an example, didn't think anyone would ever believe that the A/F ratio will always be 14.7:1, guess I should have explained further, but didn't think it would be necessary. Need fuel maps, I have them from my rotary turbo if needed, but I still don't believe that with detonation the ecu will inject more fuel, but will pull timing as far as needed. Naturally more fuel is needed when under boost to counteract cylinder pressure, but when detonation is detected the timing will be pulled, unless one has the ability to adjust/correct the A/F ratio logic, but that's not going to happen with the factory ecu, and it also is dependent on the capacity of the injectors.

Just had a Acura TL that regular was used, no more fuel, but timing was pulled so far back that even when the VVT was introduced, the car would barely increase in speed. Just a full tank of premium brought it back to life.
 

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Some say it is because the engine is purposely built with loose rings because turbo. I run a catch can FWIW.
I wouldn’t trust whoever said that because it’s ridiculous.

If there were a fitment issue with the rings you would have excessive oil consumption and other related issues.

Your catch can is good for preventing crankcase vapors (oil) and gases, usually part of the EGR system, from entering into the intake track.
 

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I have them from my rotary turbo if needed, but I still don't believe that with detonation the ecu will inject more fuel, but will pull timing as far as needed. Naturally more fuel is needed when under boost to counteract cylinder pressure, but when detonation is detected the timing will be pulled, unless one has the ability to adjust/correct the A/F ratio logic, but that's not going to happen with the factory ecu, and it also is dependent on the capacity of the injectors.

Just had a Acura TL that regular was used, no more fuel, but timing was pulled so far back that even when the VVT was introduced, the car would barely increase in speed. Just a full tank of premium brought it back to life.
Go look at your maps and you’ll see fuel demand changes with RPM, boost and load. More fuel is added by duty cycle (not the size of the injector.) Think squeezing your outdoor hose nozzle for 1 sec then again for 2 seconds.

Being naturally aspirated the Honda can manage detonation with timing, and also valve-timing as you suggest. But it likely adds a little fuel when knock is detected as well.
 

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Go look at your maps and you’ll see fuel demand changes with RPM, boost and load. More fuel is added by duty cycle (not the size of the injector.) Think squeezing your outdoor hose nozzle for 1 sec then again for 2 seconds.

Being naturally aspirated the Honda can manage detonation with timing, and also valve-timing as you suggest. But it likely adds a little fuel when knock is detected as well.
??????????Never said more fuel isn't added with increased rpm/boost, that's natural, the statement was made that when detonation is encountered, more fuel is automatically supplied, but I'm stating that when the engine detects detonation, more fuel isn't added, timing is pulled.
The Acura, no more fuel was supplied, just timing pulled way back.
 

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That's what my knowledge bank tells me. Just drop the timing back in increments till it stops knocking. That's why I asked for the relevant map that displays added fuel with detonation. That map displays air fuel ratio's in the 9's. I have never seen a fuel map tuned that rich for a NA engine and question why would you do it and loose so much power.
 

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Speaking from my Subaru experience the ECU maintained a “history” of knock and adjusted the fuel map (richened- added fuel.) That history would change over time and the ECU would attempt to return to more optimal timing and a/f ratios. The point is that the ECU will add more fuel, whatever the mechanism, to combat knock.
 

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We have purchased a 2019 Santa Fe ultimate 2.0T in Nov 2018, and I have been doing my own oil changes since. I have changed it at 2000 miles, and another time at 5000 miles, and what I have noticed is that the oil level on the dip stick would rise as more miles have accumulated. So this last oil change, I only put in 5 qt of oil (full synthetic 5w-30), and verified that the oil lvl was JUST BELOW the top mark after the change. As time went on and another 3000 miles, the oil lvl is showing about 1/4 inch above the top mark. Yes, the car was flat and cold. Has anyone else noticed this gasoline dilution issue? It is quite significant. I did go to the dealer and they want me to start changing the oil there and go back intermittently for them to check the oil levels themselves, so to document everything. Just curious about others with the same 2.0T engine. Thanks!

The oil level on our 2019 Ultimate Santa Fe 2.0T is quite a bit over the Full mark.
The oil was changed at 800 or so miles by the dealer and another 553 miles was added before an oil sample was sent to Blackstone Laboratories for analysis.
Our fears were realized, the 5W/30 oil is diluted to 20W from Fuel in the oil.

See attached report.
 

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Wow that's bad. How does the manufacturers expect that oil to get between services? Was the oil really changed by the dealer or just ticked off?
 

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Wow that's bad. How does the manufacturers expect that oil to get between services? Was the oil really changed by the dealer or just ticked off?
Because I’ve read reports of metal particles in the engine during manufacturing causing engine failures we had the oil changed after the first 800 miles.

The oil was clear after they changed it so I trust that it was really changed.
Even after only 553 more miles on the vehicle the level on the oil dipstick was far above the Full mark. That’s why the oil was sent for an analysis.

I sent the report to the dealer and am waiting for a reply. This same problem was happening to a 2013 Chev Equinox we owned for a short time. The local Chevy dealer had sad that GM had not found a fix for the fuel in the oil at that time. They tried replacing the fuel pump on the engine but that didn’t change anything.

That Equinox was traded for a 2015 Santa Fe with the 3.3L engine, that engine did not ever have fuel in the oil during the 4 years of ownership.
The 2015 Santa Fe was traded for the 2019 in July of this year. The 2019 has 1600 miles on it now. But it’s life is in jeopardy.
 

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I struggle to understand how an ounce of fuel is getting in the oil every 125 miles or so (based on 3.3% fuel dilution on report.) What kind of gas mileage are you getting? Do you ever see heavy dark gray or black exhaust?
 

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Normal blow-by will send fuel to the oil

Doesn't help that I've seen 10.5:1 A/F ratios while under boost.

Get a scanguage or obd2 device and monitor yours
 

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The oil level on our 2019 Ultimate Santa Fe 2.0T is quite a bit over the Full mark.
The oil was changed at 800 or so miles by the dealer and another 553 miles was added before an oil sample was sent to Blackstone Laboratories for analysis.
Our fears were realized, the 5W/30 oil is diluted to 20W from Fuel in the oil.

See attached report.
Was that the "Standard Analysis" that you ran?
 

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Normal blow-by will send fuel to the oil

Doesn't help that I've seen 10.5:1 A/F ratios while under boost.

Get a scanguage or obd2 device and monitor yours
More tan 3 ounces of fuel in the oil as measured by Blackstone is likely not normal “blow by” in only 550 miles of driving.

Thanks for quantifying the fuel being added to prevent knock.

Wondering if the engine oil ever sees full temp for extended periods to help vaporize the fuel.
 

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More tan 3 ounces of fuel in the oil as measured by Blackstone is likely not normal “blow by” in only 550 miles of driving.

Thanks for quantifying the fuel being added to prevent knock.

Wondering if the engine oil ever sees full temp for extended periods to help vaporize the fuel.

We took a 330+ mile trip this week.
Before the trip I changed the oil even though it had barely 1000 miles on it.
I installed one 5 quart jug and the dipstick level was midway between L and F.
To make up for the .07 of the 5 quart .07 crankcase capacity I added a couple more ounces bringing the level to just BELOW the F mark.
After the road trip the oil level was RIGHT ON the F mark. Checked with a cold engine.
The average mpg according the LCD screen was 29.9.
 

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I have a little over 1300 miles on the SF. Checked my oil this morning and it was well over the full mark and smelled of gas. I'll be taking long commutes next week - about an hour each way and see if any gas that may be in the oil burns off and the level goes down.
 
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