Marvel Mystery Oil

[John Sabato]

As I recall, if you got STP mixed with engine oil it became super slippery... in fact if you got it on your hands, it was so slippery that you couldn't pick up tools like a screwdriver or pliers... they just slipped right out of your hands. In the advertisements, it was recommended by race car drivers to make your engine run FAST as the slippery properties were supposed to reduce engine friction... but the pro race car drivers didn't bother to mention that the engines they used it in for racing were torn down and cleaned every week... so it had no chance to be harmful to your engine.

I think I also recall that it was reported that using it would eventually cause a lot of sludge to form in your engine... I stopped using it in cars around 1980..., but it does make good case lube.

I never used Marvel Mystery Oil for anything... Quaker State oil is the worst motor oil I have ever used... lots of sludge between oil changes. Pennzoil on the other hand, has always worked well for me... stays clean a long time. I still insist on it when I have someone else change the oil in my vehicles.

[Zorba]

Originally Posted by John Sabato

Quaker State oil is the worst motor oil I have ever used... lots of sludge between oil changes. Pennzoil on the other hand, has always worked well for me... stays clean a long time. I still insist on it when I have someone else change the oil in my vehicles.

And that's EXACTLY the opposite to what I've learned and observed. Go figure!

I wouldn't use Pennzoil in my lawnmower!

[John Sabato]

Originally Posted by Zorba

And that's EXACTLY the opposite to what I've learned and observed. Go figure!

I wouldn't use Pennzoil in my lawnmower!

Everyone is entitle to choose whatever oil they think is best, but here is my story in more detail...

In the mid 1970's I took my 1968 Chevy Nova to a local Augusta Georgia mechanic who had a great word of mouth reputation and asked him to change the oil and filter as my active duty commitments at the time prevented me from doing it myself...

I had always changed my oil every 4-5000 miles. (I was also born and lived in the Quaker State (PA) for about half my life...) so when he asked what oil I wanted to use, and I told him Quaker State, since it was all I had ever used...

Remember that many of the auto racing greats at the time were spokespersons for Quaker State oil and recommended it. But the same logic applies here that I mentioned above about STP.

Professional racing machines are torn down every couple of weeks and rebuilt... so the oil only has to last that long... Even though Quaker State is one of the oil brands he stocked, he said he said he wouldn't recommend that I do that.

I had purchased the car new and it had about 40K miles on it at the time... he took the time to remove my valve cover and show me the sludge on top of the head... I was appalled. Then he pulled the valve cover on a similar car that he owned since new and had more mileage than my own. The oil gallery on top of the head had NO sludge. He told me he only used Pennzoil or Valvoline oil, and he changed the oil and filter at the same frequency that I used.

You might call this an anecdotal story, but I know what my eyes saw inside those valve covers. I never bought another drop of Quaker State oil after that.

[Zorba]

Originally Posted by John Sabato

...he took the time to remove my valve cover and show me the sludge on top of the head...

Sounds like a typical Penzoil motor, I've seen a few. *shrug*

I dunno!