Run what is required. weather it is 5-20 or 5-30 in the 4.7L. dont diddle around with that.

Different brands, types or viscosity oils should NEVER be mixed. Different additive packages containing different chemicals have been known to mix and render beneficial additives inert as well as mixing together and creating compounds that cause sludge or worse are highly corrosive.

But yeah, it's safe to switch to synthetic and even back to conventional at any time...


So you think dirty oil is an indicator of when you should change it?

So a synthetic that's been tested to be able to suspend 3x more particulate than a conventional oil should be changed when it looks about the same color?

Interesting...

So in your opinion, an oil that comes out clean enough to see thru at say 3000 miles is a better oil than that which comes out damn near black at the same interval?

Actually, correct me if I am wrong, but if the oil is clean after 3000 miles, then it's not doing what it is supposed to do? There are detergents in oil that clean your engine. If the oil is darker, then it's doing it's job cleaning the engine, getting rid of sludge and contaminants, no? I thought that's how the basic principle worked.

And the answer is...

NOBODY knows, Mikey don't know, you don't know, I don't know...

Clean oil can mean the oil is NOT doing it's job in cleaning deposits or it can mean the engine is in fantastic shape and there are next to no deposits and they are extremely small.

Dirty oil can mean the oil is doing what it's supposed to and catching/suspending particulate within the oil and away from metal surfaces OR you've got an absolute mess in your engine and both the oil and filter are saturated, meaning they are already holding all the harmful particulate they can and the rest is free to do damage.

ONLY by having your oil professionally analyzed will you know for sure.

BTW, I've had it done a few times and I've seen them recommend longer intervals between changes often, BUT never nearly as long with conventional oil as synthetic. Synthetic does hold it's properties longer than conventional. Does this mean you MUST use synthetic - NOPE, just means you should change it sooner.

Does this mean EVERYONE should have their oil analyzed - NO, if you are changing it at the recommended intervals and it's neither too glaringly clean or dirty you are fine, although it's not a bad idea to test it maybe every 30k or so just so you know what you decided to do about your oil/filter brands & changes are working in your particular truck...

You are 100% correct. The oil is holding the dirt and crud in suspension, which is why the interval doesn't change. Oil gets dirty at the same rate - synthetic or dino.

If the oil meets the current standard, "SGx", it can be mixed. That's the purpose of that standard. I think it's up to "SGM"

Stick with the weight that Dodge says. If you go to light it will be to runny and could damage your engine. If it is to heavy it will not lube right either. I use Mobil 1 and have been for 9+ years. When I have taken it to the shop they have been amazed on how little wear there is. I also go 7000 mile between changes, it last longer than conventional oil, so you get your moneys worth.

I did notice that changing to synthetic actually cleaned my engine out .When I first changed to mobil1 5w-20 It started to turn black after 1,000 miles.I changed it at 3,000 miles.Then it started to turn black at 2,500 miles changed it at 3,000 once again.Then on my last oil change it started turn dark around 4,000 miles and I changed it at 5,000.It seems to run better than when I first got it.It had 61,000 on it when I got it and it now has 72,000.I also always use a wix filter.

I know it says to run 5w20 in our 5.7 hemi. But is mds the only reason for this? I was thinking once I go with a programmer and disable mds maybe I can run thicker oil?

No, the weight comes from the clearence of the bearings. It has nothing to do with MDS. A heavier oil may not lub right or right away. These newer engines are built with tighter tolerences and they were not made for the old oils. In part this comes from the fuel milage requirements.

Why would you want to run a thicker oil anyways?