Craziest thing happened to me but first a little back details...
1994 B250 with the awesome 5.2 (personally, I love the 5.2!) I have opened the van for about 6 years and in the last 2 years or so I replaced pretty much every single gasket and seal and freeze plugs. The only seals/gaskets not replaced are the head gaskets and valve seals. The valve seals have leaked since about as long as I have owned it, every morning at start up, puff of blue smoke for a half second and gone but consistently every morning routine. I purchased new valve seals to replace but have not done it yet which brings us up to current.
So a few months ago I decided to change my oil to synthetic oil, mileage was a little over 148k and every 1000 miles I have to add oil to to it off. The strange thing is that now I am able 152k miles and the last 2k miles I have not lost ANY oil. I did not use high mileage oil because all the other gaskets and seals are pretty new and didn't want to add any swelling additive to it. I only use Pennzoil PurePlus oil in all my vehicles. I really don't know why I waited so long to switch it to synthetic but finally did.
Any one else seen similar results when switching to synthetic oil? I have seen a lot about switching causing leaks but not stopping. Either way- I'm pretty happy, love my Van, love my 5.2, Mopar for life!

 

I switched to full synthetic at about 180k (from memory).
at that point I was using 1/4 of a quart every 1000 miles.
After switching the consumption had at least halved.

 

Only if you switched to a thicker weight should that have helped if we're talking gasket and oring leaks. Internally, there may be additives that help maintain compression better.

Every time I've used full synthetic it has leaked the same or worse. I have been with maxlife since 120k and engine is still happy at 257k. To each their own.

Oh, and maybe do a proof read of your text next time. I figured out what you meant but it was quite the word puzzle.

 

I changed to Mobil 1 10w30.
I was actually bracing for an increase in consumption based on what many have said, but to my surprise that was not the case.

 

There are so many variables when it comes to oil consumption that it's pretty hard to draw conclusions. I had a van that all of a sudden started going through oil like crazy. I ran an engine flush through it and changed the oil with the same brand & filter I always used. After that, it returned to its normal 1 quart use between oil changes and never did it again. I never did figure out what the heck happened, but I was just glad it stopped.

 

So, nothing major to worry about when changing from dino to synthetic oil? I have heard some people say not to use synthetic if you have been using dino oil in an older vehicle. I have a 98 5.9 with 173,000 miles, no oil leaks at all, am ready for an oil change and was thinking about switching to synthetic.

 

I’m over 220k now, on my 98 5.2... no regrets from switching to full synthetic.

 

As the synthetic cleans the engine, it will cause leaks where seals have worn. Best thing to switch to is the blends for high mileage like maxlife.