BINGO! Give the man a cigar!

 

I've often wondered about oil viscosity. I ran "straight 30" in my new 79 Camaro after the first oil change because I figured it was "better" for the engine. This engine dutifully burned a quart every 1700 miles with 30 weight.

Eventually, I changed to 10W-30 and the engine stopped burning oil(!)

25 years go by and we are now driving a Honda Civic.

Oil change at the dealer on Friday and my wife asks me on Sunday "Why is that red light coming on all the time?"

You guessed it: They FORGOT to put the oil in after the oil change (5W-20).

After a month of threatened lawsuits, letters to the president of Honda etc, the dealership reluctantly changed the rod bearings and we settled on a "free" 7 year warranty. The engine is running just fine 5 years later.

The point of all this? Use the recommended oil for the best chance of engine survival.

 

Holy crap! They forgot the oil!?! Sounds like it turned out okay, though.

 

I use 0w20. Because it will reach its proper operational thickness/viscosity faster in a colder climate.

 

There is some truth to this. As long as the oil viscosity is not causing an engine problem it will not generate a CEL. BUT, if it's out of the pre-set parameters programmed into the PCM it will generate a "stored code" which can be read.

Technically, it can be used to void a warranty claim for certain engine failures.

Bottom line is, there is a reason they spec 5w-20 for MDS Hemi engines. Why take the chance and run another viscosity oil?

 

Because running 0w20 will warm up faster to the proper viscosity faster and maintain it. vs 5w20 in a cold climate.

This in turn means my engine is getting proper lubrication faster, hence less chance of premature failure of engine components.

Again this is my personal choice. I make my own truck payments. Im not pushing my engine oil choices on anyone.

I can however post up information that made me come to my decision as why 0w20 is better for me in those climate.

 

SAE VISCOSITY


An SAE viscosity grade is used to specify the viscosity of engine oil. Use only engine oils with multiple viscosities such as 5W-20 or 5W-30. These are specified with a dual SAE viscosity grade which indicates the cold-to-hot temperature viscosity range. Select an engine oil that is best suited to your particular temperature range and variation. For 3.7L/4.7L engines SAE 5W-20 engine oil is recommended for all operating temperatures. For 5.7L engines SAE 5W-20 engine oil is recommended for all operating temperatures.These engine oils improve low temperature starting and vehicle fuel economy. Refer to your engine oil filler cap for the recommended engine oil viscosity for your vehicle. Vehicles with 5.7L engines equipped with Multiple Displacement System (MDS) must use SAE 5W-20 oil. Failure to do so may result in improper operation of the Multiple Displacement System (MDS). Refer to Multi Displacement System under Starting and Operating for details. Refer to the engine oil filler cap for the recommened engine oil viscosity for each vehicle.

 

I dont know how I can break this down any further or simplify it.
The starting viscosity of 0w20 is BETTER in cold climates vs 5w20. And it provides the same protection.

 

I've read the references that support your position and believe your conclusion to be correct. What I'm not sure of is how the 0w20 might adversely effect the MDS operation.

 

I know it's human nature to believe we can second-guess Chrysler's engineers, but they've spend large sums of money testing and validating which oil works best for their engine's they manufacture. I'm sure they've run torture tests from 100+ temps all the way down to -30, and likely even lower. It's in their best interest to specify the best viscosity oil for their engines since they have to warranty these engine's, and will cost them a significant amount of warranty work if they get it wrong.

Who do you believe has the best information in hand to make that call, us or them?

And even by chance you do get it right, is it worth taking a chance that your giving Chrysler a way out if something goes wrong?
Believe me, they will if you give it to them.
Take for example, an aquantance of mine that I race with had GM attempt to void his warranty claim with a blown engine because he decided to go with a different tire than the stock Eagle F1 RF's! And if some of you think Chrysler wouldn't void a warranty on an engine because you changed the viscosity of the engine oil from the recommended, some of you may be in for a suprise.

Word to the wise.