umm ok the 5 20 is a thinner oil therefore it will lose psi faster than the 10w30.ive used 10 30 in every car ive ever driven and they have outlasted (the same car) with 5w20.its only one grade thicker .where i live its 100 during the day and 100 at night.and if you read the manual it says 10w30 is fine for the temp ranges im in.5w20 falls about at 90 degrees.and all this was after i took it to ford and they told me to run thicker oil. because thats what i originally thought was that there was something wrong so i took her in and they said it was just too light of an oil for where i live.
If this is the case, I'd be worried if it took a different/thicker oil viscosity then what was recommended by the manufacture to turn off an oil light that I'm guessing was turned on from lower than desired oil pressure. Sounds like a "band-aid" fix. For whatever reason Ford chose 5w20 for the 5.4/6.2 is completely speculative, but the fact is, 5w20 is what the 6.2 calls for. If your 6.2 has a hard time building oil pressure when using 5w20, then there is something internally wrong with the engine; or, if you are managing to get your oil that hot, your engine must be on the brink of a melt down, not to mention the oil must be chemically broken from the extreme heat making it useless at any psi. I have a hard time believing a Ford dealer suggested this as a "fix".[/QUOTE]
I agree 100% and REALLY have a hard time believing a Ford Dealer suggested this.
FSM[/QUOTE]