I cannot get behind a recommendation to use a different grade of oil than what the manufacture recommends. The manual says in no uncertain terms that 0W-20 is recommended. Unlike some vehicles I have had in the past, which list a couple grades based on temperature of your region, the manual for this car simply says 0W-20 across the board for all regions and environments. I would like to know what basis you have to make the statement:
hydraulic timing solenoids are not designed for such a consistency
What you seem to be saying (without providing any evidence) is that the engineers allegedly built the engine for one grade of oil and then recommended another, which is a fairly ridiculous proposition. We're not talking about a new motor here either, the 2.4 is one of the longest standing engines I can think of and naturally its been tweaked and poked at over the years (like how we now have multi-air) but regardless, after all these years I think the engineers know pretty darn well how the core internals and oil work together on the 2.4.
Just to drive another nail in the coffin, the difference between 0W-20 and 5W-20 is nothing, other than at cold start. The operating temp viscosity of both of those grades is 20, period. They will function no different whatsoever once the engines are warmed up. So all you are proposing is that the engine should have more viscous (thicker) oil at cold startup, which makes no sense at all. This "heat" you worry about is non-existent at cold start, and as we already pointed out both oils are at a rating of 20 at operating temp so.. your position is without evidence and nonsensical.
I don't mean to be combative about it I just don't want other unwitting people to come here, read your opinion, and start putting the longevity of their motor at risk for no reason.
I'm not sure about your statements on fuel either, the manual dedicates no less than four pages
to talk about fuel for the vehicle in the US and the short of it is that they simply recommend running normal 87 octane fuel
, anywhere from 0 to 15% ethanol.
Actually on page 422 its worth noting the manual states "The use of premium gasoline is not recommended, as it will not provide any benefit over regular gasoline in these engines.
You are entitled to your opinion and recommending premium fuel isn't so bad as you are more just telling people to waste their money vs telling people to use the wrong grade of oil in their engine but still, I have to point it out for whoever may come here doing some reading in the future.
My personal opinion is that the engine would never know the difference between 0W-20 and 5W-20 unless talking about a vehicle being operated solely in an extremely cold climate which is not most of us, and even then I doubt you could measure much difference in overall wear until about the 100,000 mile mark, but its just the principle and the protection of the warranty that I am thinking about. If I accidentally bought and ran 5W-20 in my Jeep tomorrow and realized it a day later I would not even bother to change it out, the differences are virtually nothing especially now that it is summer, but I would not run 5W continuously on purpose and brag to Jeep about it because I don't want them to have any excuse not to honor my warranty out to the last day or mile, thats all.