Thanks for the VR1 enlightenment.

Yes, I'm an old codger and remember seeing some torn apart engines that had seen lots of STP back when it was more popular. In the sixties, when you tore apart an engine to find huge hunks of tar everywhere, you knew that the engine had seen one or more of three things: Amalie, Havoline or STP. To be fair to STP, it might react differently mixed with todays engine oils.

If STP were indeed an adequate source of ZDDP, I would only use it for break in, not for the long haul.

Engines that were sludged, but without the black (actually grey) tar look, were probably just victim of inadequate oil change frequency.

 

That's why I run Torco. They make oil with all the right additives for street or race use.

 

MBdiag,
I noticed your avatar says you have a 2006 GT. Is that the car you're
concerned about ZDDP? I have wondered if the newer hi-performance cars
maybe getting more crank berring wear than they should. My DD is a '07 Hemi Magnum
and I was concidering some ZDDP for it. Might be better to have less engine wear rather than a cat that lasts 150K.

I took off the top of that engine that had the gunk, in the early 1980s (yea, I've been "around the block" many times too!). I can't remember if the gunk was grey but the PO said he "took good care of it" and added STP.
It was a 1971 Challenger convert, so I had to buy it anyway! (wish i'd kept it).

 

i use VR1 here as well 20-50. can even get it over here, so for me it's the simplest thing

 

Our Advanced Auto and Napa carry the ZDDP Plus additive.

 

You are very observant.

No, my ZDDP needs are for a 64 289 that I'm building. Don't tell anybody, but it's not in a Mustang. It's in a Galaxie 500 Fastback. I come to the Classic Mustangs forum for good small block Ford discussion. The Galaxie forums don't discuss anything but FE's.

In any modern V8 such as my three valve 4.6 or your Hemi, any modern Premium motor oil, changed regularly, is totally adequate IMHO.

Yep, anyone who had any early Challenger, most especially a convertible in ANY condition, wishes they had it back. I say this literally, if I had all my cars back to sell at todays values I would be able to retire VERY comfortably.

 

Ah... to have my old cars back... hindsight. 20-20 they say. :0

 

ZDDP is bad for cars with cats, IIRC.

 

MBdiag,
Those G-500s are cool. You're certainly welcome here.

69mach1377,
The standard that reduced ZDDP in oil is only about 8 or 10 years old.
Cars started getting cats back in 1975, so it can't be that bad for them.
With the new oil, the cat probably lasts the life of most cars rather than
clogging up at about 90-120K miles.

 

I agree with 71Mach. Cats have been on cars since '75, so there was about 15 years of normal ZDDP levels with no cat problems. Further than that, an engine in proper running condition will see no zinc in the exhaust stream anyway. An engine with lots of blowby will allow a LITTLE bit of it. In the case of blowby, the oil vapor will probably do more to damage the cats than the zinc.

The cat damage claim is just another excuse to take the stuff out IMHO. For who's gain I'm not sure.