Anyone ever notice that the owners manual says to use 5w40 synthetic, but the oil filler cap on the engine says to use 0w40 synthetic? I don't suppose there is too much difference between the two, but it got me wondering.

I used Castrol Syntec 5w40 for the first oil change today, but think I'll change to Mobil 1 0w40 next time.

What oil viscosity do you guys use?

Thats what i use too. Castrol that is

Mobil 1 15w50

Amsoil 5W-40.

Newfie.

Mobil 5/30

I have used Mobil 1 0W40 all along and 15W50 in the summer

mobil 1 ow-40

Anyone ever notice that the owners manual says to use 5w40 synthetic, but the oil filler cap on the engine says to use 0w40 synthetic? I don't suppose there is too much difference between the two, but it got me wondering.

I used Castrol Syntec 5w40 for the first oil change today, but think I'll change to Mobil 1 0w40 next time.

What oil viscosity do you guys use?

I think what you're seeing is Chrysler changing from Mobil 1 0w40 to Pennzoil 5w40.

The factory fill is/was Mobil 1 < not sure what factory fill is today.

The service fill is now Pennzoil Platinum... not available in 0w40.

There's the story... Chrysler is probably trying to use up all those Mobil 1 labeled oil fill caps they have in inventory.

^^ So use either 5w40 or 0w40...

0w is preferable for colder climates -- thinner than 5W at cold startup. I would not go below 40 though -- better protection at operating temperatures than 30 or 20 weight due to better shear strength values and film thickness at the expense of more friction.

The difference between 0ww and 5w will not make a difference unless you live in a climate where it gets around 30 below 0.
I run 15w-50 in my 426.

I use 0w-40 all year.

0w40 all year.

Royal Purple 10W-40

ow40 royal purple on the next. Right now mobile one 15w50 for summer