ZDDP Question

yes, so far sounds like 10w-40 or 15w-40 , just have to look at the data a little closer to get apples to apples. specs have changed , epa regs have changed so you almost have to throw alot out the window and hope the man following too close behind you.

Rotella and Delo are on the shelf at Walmart, SAMs and most parts stores and has the ZDDP in 15-40W. Less than $20 per gallon. Not hard to find and it works.

I was referring to the sae 40W not as easy to find it "on the shelf" not any current engine that probably specs it besides some tractor or generator. its got delo 40w last time I changed it after I bought boat last year.

Just to state a fact, Detroit designed those 2 stroke Diesels 50 years ago and that 40W was probably the best option, back then. 50 years later in 2018 if you go to any Diesel Repair or Parts house you see 15-40W on the shelf.   These Brand new Diesel engines still require the ZDDP in the oil so even the 15-40W has it and these Diesel repair and parts houses do not stock straight 40W any longer.
Buy Joe Gibbs or Royal purple if you wish but the 15-40W Diesel oil will work for you just fine.

Like I've said before,   add a can of Lucas ZDDP additive to your favorite oil and forget about it.   That is what it is made for.

Duane in Indy wrote: Like I've said before,   add a can of Lucas ZDDP additive to your favorite oil and forget about it.   That is what it is made for.

+1 on what Duane sez...

Duane in Indy wrote: Like I've said before,   add a can of Lucas ZDDP additive to your favorite oil and forget about it.   That is what it is made for.

At $14.00 a bottle/per oil change, I'll stick with using oil that already has ZDDP in it.

Duane in Indy wrote: Must be a cold hard winter to have beat this thread so long, and to have done it last year also.

Duane,
I'm sure it will continue with more winters in the future!

rosconole wrote: 15w40 marine & diesel amsoil since I can use the same in powerstroke and buy in 5 gallons at a time @ 133 for my dealer price.

Great price. I pay $90~ for 2.5 gals at NAPA.

I didn't know you can buy Amsoil at Napa? Thought it had to be through a dealer.

I used the Amsoil Diesel & Marine 15-40 in a Suburban diesel that I did a test on with the help of an Amsoil dealer, we did uoa on every change. It's an outstanding oil.

TRBenj wrote: $9/qt, ouch.

Yeah, but we get 2-3% increase in RPM with it!

That's not as good.

rosconole wrote: ZDDP is actually only specd at break in so its a moot point now really. .

Ross,
Lots including myself have a different opinion. I have seen first hand the damage done when non ZDDP oils were used on well broken in flat tappet engines.

MrMcD wrote: Ross, Pete is correct. If you don't want to use zddp install a roller camshaft and lifters. Flat tappet cams need zddp for protection against wear. Mark

Ross,
Hopefully you haven't gone to a non ZDDP oil!!

If you guys are gonna disagree with Roscoe, could you at least get your info straight.

You talk about motor oil with no ZDDP................all MOTOR OIL has ZDDP in it. Some have more than others

The newer passenger car motor oils have 700 to 850 ppm zinc and the generally accepted magic number is around 1100 to 1200 ppm for older flat tappet engines.

I figure, to each his own, if Roscoe wants to run a lower zinc oil he can take his chances, it's his engine

I'm still trying to figure out why the Jeep Cherokee I had that fell apart around the engine was still running just fine with 250,000 plus miles on low ZDDP/zinc oil of around 800 ppm. No camshaft /lifter issues, just good old salt related rust issues.

Here's a link to the PQIA website where you can look at the oils they tested and see zinc and phosphorus levels in both the passenger car oil section and the diesel oil section

PQIA