There is still diesel oils with enough zddp being made still. Pay attention to what you buy and what is the problem?
As for the right WT, per the 86 manual for my truck ford recommends a 10w-40 for temps above 0F
and if they remain consistent below 0F than 5w-30 so my 5w-40 is good year round (does it need said?) it's the first number for cold weather
The issue with adding additives, is if you use too much you can do as much damage as not enough.
I'd rather choose an oil that gets it close than have too much.

 

On the synthetic vs. dino oils.... synthetic WILL seep through cork gaskets no matter how well installed. The pores on cork will swell closed with normal oil, but synthetic just flows through.

 

Yup. 5 qts + 1qt with filter change —>6qts. We always put 6 qts in trucks when I worked at the Ford dealership in the 90’s


10W-30 synthetic blend in my trucks year round. I used to use Motorcraft oil and filter because well, it’s Ford oil. Now I use Havoline because it is a better price but everything still gets a Motorcraft filter.

 

thats a myth. If your gaskets are good they are not going to leak.
don't take my word for it, just search.

 

The first 8 or ten links I saw were all anecdotal. They ranged from "my 19xx XYZ model leaked 10 minutes after oil change" to "I've run syn in everything for 10 years and not a drop ". I sure would like to see some real testing and results, but I have yet to find any.

The only post I saw that got me thinking was one that suggested the higher detergent in syn might be flushing the sludge sealing gaskets away. I have zero evidence of this, but is an interesting hypothesis. And if true, may be the reason for such wildly differing experiences....especially if the engine was not freshly rebuilt.

 

Dang. I was hoping to sneak that one in and not get banned. This is a sad day.



This is what I've always heard. I personally don't run synthetic in my flat tappet cam engines. The internet rumor said that synthetic was "too slick" to allow the cam to rotate the lifter properly. So I have always stuck to dyno oil with an additive. I know it works and many engines live a long life eating the stuff, so the risk vs reward just wasn't there.

 

When I mentioned the synthetic tending to leak, I meant to say if I didn't before, that I already have leaks and burn some oil, and the synthetic seems to make the usage worse. I didn't mean to say that synthetic causes leaks.

 

I use it in my 86 460 and I notice no more leaking than when I bought it. I bought it with a rolled odometer and believe it had 132k it now has 141 and has had diesel synth the whole time. With the detergents in diesel, it should be leaking out of every gasket/seal at this point if it was sludge keeping it from leaking. (hope I don't jinx myself arg)

The only real testing you're going to see is to try it yourself. How would you test? Take a leaky motor and put synth in it and see if it leaks more? It probably will.
If it isn't leaking, than it most likely won't. Send the request to project farm he might take on the challenge.
He might have actually done this with seals already. I think that test was just if high mileage oil did anything to seals at all.

 

I dont know what you guys are doing as I thought this thread would be up to 6 to 8 pages by now like most posts of this type go to
Dave ----

 

I too, was hoping this would not turn into one of those... In the end, oil is oil. Just use a decent oil and filter and change them when you should.

 

when you have to fix others bad advice it tends to drag on.