i dunno man, i have a hard time switching from something that's never let me down.

 

So Mobil 1 at this point is the Top Choice of the Mustang Forum and the general consensus is DONT USE PENNZOIL.

 

Mobil 1 20W50. Everything else they have is API certified (low zinc)

 

Fair enough, but I don't think using an I6 as a base comparison is fair. Those things are borderline indestructible:P Hell, they'll run without oil for quite a while.

 

It's not just Pennzoil, Any Paraffin-base oils.
Quaker State, is one of the worst. Think "WAX"
sure it flows when it is hot but when it cools,
it leaves the waxy residue known as "sludge."
Just great, until the oil pick-up screen is clogged.
Their synthetics are probably safe to use, if they
are 100% synthetic. The diesel synthetic oils, are higher in zinc.
I got a supply of a Canadian 5W-40 diesel syn.
that I also use.

Eric

 

I've heard they will. People tell me stories about things like this when they see I have an I6.

 

The I-6 motors run forever by design. The piston goes up and
down against gravity. They also have 7 main bearings.
A V-8 has gravity wearing on one side of the piston and 5 main bearings.

Eric

 

I had just started to type this very same fact. My dad was in the oil business and he always said to avoid PA crude as the paraffin was not good for your engine. It is a bigger issue if you don't change your oil frequently, so most on here should be okay. I would still switch if you are using Quaker State, Pennzoil, etc.

Also, only use synthetic after your engine is broken in. I usually wait until somewhere around 2000 miles.

 

2k is too early to switch to synthetic. It usually takes 8-12k miles to completely break in all of the friction surfaces in a motor. This is the opinion of several oil companies, as well as cam manufacturers.

 

20k is more in tune before the switch, synthetic's usually all but stop the wear since their molucular structure (bigger) and adheision properties (stickier) are much better than the dino oils. I never use Quaker State or regular Pennzoil. I will say that the Pennzoil Platnum full synthetic is a great oil and held up better than most all of the over the counter motor oils. About twice as good as Mobil 1 in testing (ASTM D-4172). Also, if you have an older engine, you may want to check into a non-detergent synthetic. Most of the synthetic's have enormous cleaning abilities and when used in an older engine, it will clean the varnish that is sealing the engine from the inside, and you may spring a leak.