Good article on LSPI, worth a read

[Snox801]

well, first of all, I checked and Motorcraft 5w-30 synthetic blend is SN+ rated so someone just following the basic maintenance schedule at their Ford dealership is going to be fine. but I just love a good technical discussion/debate despite my earlier short, flippant reply. and I definitely do not like this credit in the article: Images courtesy of Driven Racing Oil, Amsoil and Total Seal

so here goes...

there are 4 theoretical conditions identified in that article. if I may summarize:
1. carbon deposits in the intake tract detaching and forming a hot spot. could definitely happen. carbon buildup is a known issue of gas direct-injected engines.

(discussing #2 intentionally last)

3. oil and engine temp. says to warm your engine to at least 100C, obvious, yet still some don't follow this simple process.

4. lean air/fuel ratio. we know that fuel economy comes from modern engines running extremely lean at part throttle and yet surviving. this is a really good reason to run 91+ octane in your ecoboost engine, even if it's stock.

and #2 - the presence of oil.
2. tiny amounts of oil getting past the rings (it would have to be both oil and compression rings, which a healthy engine should not do) and then this mixes with atomized fuel/air and causes a hotspot.


let's think on that a moment. is oil more combustible than gasoline? clearly not. if a few microns is atomized and mixed with gas, would we really expect the flashpoint to decrease? It seems to me that the presence of oil would be more likely to lower combustion efficiency rather than cause pre-ignition.

So I’m not sure anyone said anything about the brand of oil except you. Hence the question. Yes motorcraft does indeed work. Never once did I say it had to be amsoil. Simply sated they were one of the first to offer it. You are really coming off as blatant against it. Not one single person in this s thread said anything about any specific brand until it was deemed an amsoil add. Which if you read the article clearly is not. Then they use a generic base stock picture of a well known oil. If they used a motorcraft picture would you have said the same thing nope.
Moving on to your point one. Like oil they state it can cause it but not the main factor. True but if a better oil and fuel is used to help reduce the carbon the better. Fact is better oils produce less vapors and evaporation than less quality oil regardless of brand or price. When they bake off it moves through your pcv system and into your intake. If we can minimize that we are one step closer to eliminating lspi.

Your point 2 assumes oil is from the oil getting past rings. Even healthy engine have that to a degree. But you are again missing the point that oil enters through the intake also through the pcv system. Both can and will cause carbon. The amount of that can be affected by how good the oil is. Far more oil gets into the combustion chamber through pcv than the rings on most newer motors.
Point 3 I’m sure we all agree on.
Point 4 is accurate also but lspi is usually the first issue causing and issue with the leaner burn. And the Oct rating simply will not affect that. Octane has zero to do with AF ratios in the terms we are talking. 91-93 only prevent detonation from timing and boost. The af ratio will be the same not matter the Octane. So the grade of fuel is not gonna save your lspi.
Hence why every RS owner was running 91-93 still had it.

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[Snox801]

I generally respect your experience but there's absolutely no way I would believe that a particular synthetic overpriced oil would have any effect on pre-ignition.

This is what I think I was hung up on.
I never said one oil was the cure. Simply stated that oil plays a role. Based on the simple fact every manufacturer has said it and crafted oils around it.
Not sure I took the article as saying that one oil was the answer also. We clearly know many that work. The key term over priced oil is what gets me. What’s overpriced? I’m sure at some point someone could argue that motorcraft is over priced compared to the local gas station brand like speedway?
The real question is what are you willing to pay for and is it needed. Lots of online oil test have laid out how different oils can compare. Like project farm. Yes some oils did much better in his test. Does that mean the other oils work work just as good in real world. Nope but gives someone a baseline to form an educated decision. Thats all I was trying to get at.
A little clarification on your overpriced oil stance would be nice. Is motorcraft the benchmark for you or is it as long as it meets specs and is cheap? I see the value in those prospectives also. We all form our own opinions based on what we consider the right choice for us.

 

[colinl]

I was kind of being a dickhead about that, true. I am a fan of high quality suspension oils, but motor oil.. motorcraft or mobil1 do the job just fine, for far less, and the change interval matters a lot more than the oil with a dinky 8 oz spin-on filter.

excellent point on the pcv and I think that sounds like a good reason to get a catch can.

 

[Snox801]

I was kind of being a dickhead about that, true. I am a fan of high quality suspension oils, but motor oil.. motorcraft or mobil1 do the job just fine, for far less, and the change interval matters a lot more than the oil with a dinky 8 oz spin-on filter.

excellent point on the pcv and I think that sounds like a good reason to get a catch can.

I agree oil change interval is probably the most overlooked. I’ve had great luck running amsoil in mine out to extended intervals but after some oil analysis to say it ok. Heck I ran one for over 400k at the 15k mile intervals. Whether that ever saves any money well who knows cause like you said the cost.
I just thought adding some clarification to what was expensive might help. To me it doesn’t bother me to buy the top brands at higher cost. Even if it’s to only make me feel good. But I have literally seen guys on the focus forums say motorcraft is to expensive then link Kirkland or some sort brand for Walmart. Which clearly does not meet the standards but is cheap.
Mobil 1 is always a staple brand and has proven to be great oil. It actually seems to be the benchmark that others judge by.

 

[Boosted]

Neither of those help with lspi. The tune can definitely help, along with oils and fuels. The cooler plug keeps those and surrounding area from damage. And the smaller gap is only to keep the spark from being “blown” out with the heavy charged air.

What Spark plug and gap is 1 step colder than stock

 

[Snox801]

I run ngk LTR71X-2. Or 6510 ngk number.

I gap them at either .026”-.028” doesn’t matter

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