Just curious if anyone else adds ZDDP when they do an oil change, sense for the last year or so, it has been excluded from oil.

So what say you all?

 

Funny how some of the boutique oil refiners are now charging $8, $10, $15 a quart or even higher for the same same oil that everybody used to refine just a few years ago for under $2 a quart.
Most of my vehicles have roller lifters, so I feel there is no need to add extra ZDDP. However, I do have a '71 Cougar that gets a combination of 15W-40 diesel oil and topped off with SLOB. (Street Legal Oil Boost) SLOB has been discontinued for several years and was last sold at Big Lots in the clearance section. I still have about 20 bottles left.
My next 393 buildup going in my '78 Zephyr will be using roller lifters and I will not be making a specialty blend.
My uneducated gut feeling says a regular flat tappet camshaft (after break-in) does not really need extra ZDDP. But a radical flat tappet camshaft does need the extra petroleum additives that the refiners now leave out.
I still feel that a lot of aftermarket flat tappet camshaft failures are NOT from the oil, but from the cheap Chinese blanks that the camshaft grinders are using.
My $.02 worth.

 

Why would you need it, most modern oils use moly disulphide, no need for anything else.

 

Actually I have been using STP additive with ZDDP with each oil change, no ill effects so far, and I want to keep my engine going for a very long time.

 

zinc and phosphorus compounds in motor oil have not been totally removed. they've only been reduced by about 25% to less than 1000 ppm to protect the catalytic converter from metallic compound damage from the high ZDDP levels.

even diesels have cat. converters now and run well on lowered ZDDP levels oils with their high spring rates flat tappet cams such as the Cummins in my Dodge. oil companies and the additives companies such as Lubrizoil have changed to boron and moly additives for high pressure and friction modifier products, higher in price but just as effective.

little short distance no warm up driving and an effective clean air filter and no air leaks in the intake system are far more important to long engine life than ZDDP levels.

 

Hi, 93nighthawk - I thought about getting a ZDDP additive for my '89 3.0, which has flat-style valve lifters. I decided against it because of possible damage to the catalytic converter. If your engine has roller-style valve lifters ('92 and later?), I don't think you would really need it.

Cheers, Mike

 

Valvoline VR-1 racing oil has higher levels of ZDDP.

 

Just about every cam mfg/grinder recommends adding ZDDP (and sells) to the oil...ron Iskenderian, Iskenderian Racing Cams (with whom I personally spoke to last year about this when all the hoopla started) advised to use 1/3 of a 6 oz bottle with the mod motors, the whole bottle for pre-mod motors (without cats.

 

FWIW, I recently tore my 1956 F350 272 CID virgin Y block down. The original Ford script valves were not recessed,(unleaded gas) very little cylinder wear, very little bearing wear but several worn cam lobes(little or no ZDDP). The rest of the valve train was in great shape. I've drawn my conclusion. It will have ZDDP of some sort in the oil when it comes back to life again.

 

i'm adding a shot glass of STP to each oil change.

it replaces the missing ZDDP and it doesn't change the viscosity of the oil much.

I will report back if/when problems surface.

 

I have a 1996 Aerostar, 4.0 engine. It has a roller camshaft, and gets the recommended Valvoline 5-30 oil.
I have a 1997 Ski Nautique, 351w "GT-40" engine. flat tappet cam, I use Valvoline VR-1 40 racing oil for it.

 

I have a ton of questions and it seems like we are close by ?