Petroleum vs. Synthetic Motor Oil. Waddaya use?

[kudakidd]

A question recently asked, piqued my interest in knowing what most of you use in your CLASSIC Mopars. Don't care about your daily drivers, just your beloved Mopes. I'll start:
Petroleum (Valvoline Racing) 20w-50

[Oldschool]

      The Beast takes the same thing KK---Valvoline 20W-50.  Good stuff

[MEK-Dangerfield]

Mobil One 10W30.

  Mike

[Chryco Psycho]

Castrol Syntec 5w-50

[71fish]

Mobil-1  5w-50

[Mopar73340]

I use MOBIL 1 in all my vehicles

[Cannibal94]

Valvoline 10W30

[firefighter3931]

Vr1 20/50 racing oil here. 

Ron

[Stacked440]

For first start im using Valvoline 10W-30 as you don't want to run synthetic the first oil change or 2, you want your rings to seat well in the cylinders, then im moving to an all synthetic Amsoil

[KellysCuda aircard]

Royal Purple  ... , freakin oil change takes a home builders loan.

[Got JOB]

Hav-O-Line 10w30 in all three. All are 340's

[dimples]

Royal Purple  ... , freakin oil change takes a home builders loan.

 

Royal purple here too, 30W, and 10-40 for the trucks in the winter.
The oil burner gets the cheaper 5W30 Mobil synthectic.

[matt63]

Hughes Engines has an interesting bulletin they send out with their cams.  It basically says that the newer SL/SJ/SM/EC grade oils have far less anti-wear additives than is required for flat tappet cam engines as this reduces catalytic converter contamination.  The lower zinc/phosphorous levels can cause premature wear especially in the camshaft.  They recommend an additive such as Federal Moguls Engine Lube.  Synthetic oils are not recommended for flat tappet cams.  The engine shop I have used says that they have seen many cam failures in recent years and attribute them to the lack of adequate lubrication.

[dimples]

If that is the case, then running "C" rated oil's, such as DELO, Del-Vac, Rotella, or "C" rated oils for diesel engines would be better, right?
(Higher Zinc and Phosphate levels)
Royal Purple "Synerlec" is also made to cure these problems with the newer oils.

[matt63]

If that is the case, then running "C" rated oil's, such as DELO, Del-Vac, Rotella, or "C" rated oils for diesel engines would be better, right?
(Higher Zinc and Phosphate levels)
Royal Purple "Synerlec" is also made to cure these problems with the newer oils.

I dunno about the diesel oils.  They have other requirements such as keeping the soot in suspension.