I will give comments on your list.
1. Yes, 6.2 is built on Premium fuel.
2. No, this is not necessary if you use Premium Fuel.
3. Range DFM is a pointless story because the DFM system itself works, it is just not active. If you want to remove DFM, you need to do it at the level of mechanical removal, software removal will not solve the problem.
4. This is the same as point 3, L9 simply does not turn off the cylinders, but the DFM itself is present and working.
5. maybe, on the other hand, why? The oil ends up going to the catalyst and burning there.
6. Here everything is debatable, our observations say that the DFM system dies on oil with idex 40, the transition to GM in this case is a choice of the lesser of two evils, yes, the engine probably will not die from wear of connecting rod bearings at a mileage of 10-20 thousand miles, but the DFM will start to fail at a mileage of 70-80 thousand miles, but this will most likely be after the warranty period. So, I continue to drive on oil 0-20. I talked to mechanics, they said that it is not worth switching to 0-40 oil.
7. There is no point at all, modern oils retain their properties for 7-8 thousand miles without problems. In Europe, there is a Longlife standard, where the oil is changed every 20-30 thousand kilometers. And cars there travel 300-500 thousand kilometers without problems. I change the oil according to the regulations, every 7,5 thousand miles.
8. This advice is really stupid, any driving or starting of the engine wears it out, so now, don't drive at all? Lol)
9. This is also stupid, yes, the engine must warm up systematically so that the temperature gaps take their place. And when a cold engine is given a little load, wear appears. Everyone knows that the worst thing for an engine is a cold start, even the engine software counts the number of these cold starts. So only warming up, even in summer, 1-2 minutes of warming up before moving off, and in winter 5-10 minutes of warming up is mandatory.
10. Yes.
11. Yes
12. This is also not necessary, it is enough to check the oil level on a white paper napkin. Metal particles will be immediately noticeable if they are present.
Well, in general, as a summary, I would not be so active in giving advice in public that is so clearly different from the manufacturer's recommendations. I understand that we are sharing opinions here, but the Manufacturer will be held legally responsible for his recommendations, and we will not answer to each other here.
@Vladimir2306
You clearly do not have the full understanding and automotive background to really understand what you are saying here. I have been in and out of the automotive industry for a very long time. While I am not currently "in" the automotive industry, I have a number of very good and knowledgeable contacts in different sectors on the auto industry from the manufacturers to subcontractors and consultants to the automotive industry.
Additionally I do not think you grasp how many of the vehicles are used in the US. We do not and cannot go driving down the highway at 100-120 MPH for hours on end. There is just too much traffic, too much enforcement and too few roads that are deserted enough to drive in this way.
This being said I will counter a few of the things you disagree with.
#2. Fuel System Additive - An additional fuel additive is a wise idea, do you need to run this, probably not its user/owners choice, but understand the fuel blends across the US are not consistent and given the fact that the fuel injectors are now part of the combustion chambers on DI engine as well as deposits formations from both oil and fuel will start to foul up injectors, piston ring groove and also develop on the pistons. I have spoken with a number of people in the petroleum industry and this is a recommendation from all of them. It is a maintenance item.
#3 & #4. DFM countermeasures - Well you clearly do not understand the PRIMARY problem with the DFM system is 2 different problems. The collapsible lifters are 1/2 of the problem, the other 1/2 of the problem is the needle bearing in the lifters. As for the collapsible lifters having a DFM bypass, even if it may not disable the lifers under DFCO (Decel with Fuel Cutoff) you significantly reduce the number of activation cycles. Like anything mechanical, the fewer times something is activated, the longer the item is likely to last. Then there are the needle bearings in the roller lifters, this is a MAJOR source of failure for the AFM/DFM systems. Even if you remove all of the AFM/DFM parts, if you replace the lifter with OE lifters from say the 6.6l these are still needle bearing roller lifters. If you expect longevity, bushing based roller lifers are probably a better option. So either a DFM bypass and/or running the transmission in L9 will prolong the life of the engine and limit the number of cycles the lifters are activated. Additionally I firmly believe that operating on fewer than 4 cylinders in the 5.3l and 6.2l aggravates the bearing failures if these engines. It may not be the entire reason the bearings are failing, but operating on fewer than 4 cylinders does not help matters.
#5. Catch Can - You clearly do not understand what a Catch Can is doing for the intake path. Additionally it is better not to try to burn off oil in the catalyst as the oil and additives in the oil will take a toll on the catalyst in the long run. The primary purpose of running a Catch Can is to reduce the amount of oil vapors that are brought into the intake path and limit the carbon build up in the intake ports and on the back of the intake valves. This is clearly a preventative measure that will hopefully reduce or eliminate the need for removing the intake manifold and having to clean the intake ports and intake valves.
#6. Do not run 0W20 engine oil. This is for many reasons, but these engines load the engine bearings with too much Torque, operate on under 4 cylinders, fuel diluted 0W20 is no longer 0W20 oil, it is something like 0W10 or just 0 weight oil depending on how much fuel is in the oil. You seem to think that 0W40 will harm the DFM lifters, the oil is not hurting the DMF lifters, it is the lack of changing oil enough and dirty oil and oil contaminated with fuel and water. Sludge and varnish build up are the primary enemy of the DFM lifters, not the oil viscosity.
#7. Changing the oil every 3000-4500 miles. Sure there are oils out the that claim they can go between oil changes between 10,000-15,000 miles, but why even bother. If you are doing only highway driving in warmer climates, this might be fine. BUT understand it is the fuel, water vapor and even soot from gasoline DI that is becoming a problem. You need to understand that most vehicles are really driven under SEVERE conditions. Too many short trips, too much time idling, too big of an ambient temperature swing. Do what you want, but oil is cheaper than steel.
#8. Do not drive the vehicle for less than 30 minutes when the ambient temperature is under 45F. This is really good advice, but you clearly do not think so and probably do not understand the reason behind this. I have logged the engine oil temperatures and found that is take 30 minutes for the engine oil in these engines to reach 200F. If you are making a bunch of 10-15 trips with long stops in the Winter months, it will kill the engine oil and if you do not pay attention, you will quickly kill the engine with this behavior.
#9. Do not start the engine and allow it to idle for warm ups. Maybe I should have been more clear, starting the engine an allowing it to idle for 10-15 minutes is not a good idea. I believe you were the one that told me that the engine oil warms up much faster than the engine coolant. I clearly stated this was not correct and have provided countless graphs proving that engines warm the engine oil up faster when driven than when idling. Starting the engine and allowing the engine RPM to drop to the typical idle speed then proceeding with a trip is the best thing to do. Now maybe in a Siberian Winter, this may need an engine heater, but for most of the US where the Winter temps are usually no lower than 0F, this is the best approach. Too much cold idle generates more fuel dilution in the crankcase.
#12. Get a magnetic drain plug and install it. This is a VERY wise idea. If you wait to see metal on the dipstick you are far beyond the danger zone. The magnetic drain plug can and will catch particles as well as allow you to gauge what is going on insider the engine based on iron/steel build up on the drain plug. We are talking like $9 USD for an OE style drain plug that used to be standard equipment or $25 USD for a rare earth high quality drain plug.
Hey, you and everyone else, do what you choose to do. But I am putting the information out here for people to consider and use as the feel fit. They do not have to agree with me, if they don't, keep it to themselves and move along. If they have questions, I will answer them. I have accumulated my knowledge over many years from classes, hands on repairs and modification on my vehicles, making a living repairing vehicles, making a living working for auto manufacturers in central offices and in the field, having discussions and learning from industry professionals, doing quite a bit of high level diagnostic work and even pulling data to review and track performance as well as failures along with quite a bit of trail and error. So I have a pretty good grasp of what is going on in almost all systems within vehicles and also why the industry makes the choices they make. Understand that many of the industry choices are not made in the end users best interest!