What are the practical differences between 5W20 and 5W30. All the paperwork for my engine makes it seem like the car will explode if I use the 30 instead of the 20. I mean, they make a point in stating how important the 20 is for my engine and for the thing to work properly. It's the Chrysler 5.7L engine with the thing that makes it only use 4 cylinders sometimes to save gas. I forget what it's called. Anyway, the paperwork that comes with the car says for that thing to funcion properly, the engine needs the 20, not the 30. It also recommends 30 for the smaller engine, but 20 for the big 5.7. Why? What's the deal?
And the reason I'm asking is because I've heard of dealers--the official service guys-- in Australia using 5W30 because they can't get 20 there. Or something.
And I just got back from my 200 dollar oil change.... yes, 200 fucking dollars. I'm doing it myself from now on!! Holy shit.
Anyway, I just had my oil changed at an authorized service representative (a mercedes dealership). They used 5W30... and charged me like they used 5W24Karat.
I think I should trust Germans when it comes to automobiles. But I also have the manual saying otherwise. What's the deal.