Oil change

[Jacob]

This is a weird question. What kind of oil should I use. I’ve heard just normal 5w-30, but I’ve also heard shell rotella 15w-40. What should I use?

[jtschug]

At the time they were new, Ford called for 10W-30. Oil has changed since then and for the last 10 years or so it has contained less ZDDP aka "zinc". This is absolutely required to break in a new flat tappet camshaft, but on a used engine with standard valve springs it is optional. You can buy ZDDP additive, and if I didn't have a roller cam, I would probably be adding it at every oil change. Many people recommend Rotella because it is made for Diesels and contains more ZDDP that regular motor oil. I've never used it, so I don't know.

[64ZCODE]

This is a weird question. What kind of oil should I use. I’ve heard just normal 5w-30, but I’ve also heard shell rotella 15w-40. What should I use?

I use Mobil 1 15W/50 full synthetic. It does have ZDDP. Whatever viscosity you choose, full synthetic is the way to go.

[Jacob]

This is a weird question. What kind of oil should I use. I’ve heard just normal 5w-30, but I’ve also heard shell rotella 15w-40. What should I use?

I use Mobil 1 15W/50 full synthetic. It does have ZDDP. Whatever viscosity you choose, full synthetic is the way to go.

I know that the older engines weren’t “designed” for synthetic oil. I assume because you use it it’s safe to use, but is it better than a conventional counterpart?

[64ZCODE]

This is a weird question. What kind of oil should I use. I’ve heard just normal 5w-30, but I’ve also heard shell rotella 15w-40. What should I use?

I use Mobil 1 15W/50 full synthetic. It does have ZDDP. Whatever viscosity you choose, full synthetic is the way to go.

I know that the older engines weren’t “designed” for synthetic oil. I assume because you use it it’s safe to use, but is it better than a conventional counterpart?

Definitely. Synthetic oil reduces friction which means longer engine life and more power to the wheels. A few years back, Mustangs and 5.0 magazine did a dyno comparison of a 302 motor with non-synthetic oil and then with full synthetic oil. The engine with synthetic oil ran 5 HP more than the engine with standard oil.

There were leakage problems when synthetic first came out but the formulations have been changed since then.

[Jacob]

I use Mobil 1 15W/50 full synthetic. It does have ZDDP. Whatever viscosity you choose, full synthetic is the way to go.

I know that the older engines weren’t “designed” for synthetic oil. I assume because you use it it’s safe to use, but is it better than a conventional counterpart?

Definitely. Synthetic oil reduces friction which means longer engine life and more power to the wheels. A few years back, Mustangs and 5.0 magazine did a dyno comparison of a 302 motor with non-synthetic oil and then with full synthetic oil. The engine with synthetic oil ran 5 HP more than the engine with standard oil.

There were leakage problems when synthetic first came out but the formulations have been changed since then.

Thanks, I’m glad to hear this from more than just some random article.

[Rt.146]

Valvoline VR1 has a high ZDDP rating. Adding ZDDP as an additive by itself can cause mechanical problems by adding too much. Modern detergent oils wash away the ZDDP.

[JamesR]

There will be many different opinions on engine oil for old cars, and probably a good deal of overlap in correctness about the right type of oil to use. Condition, set up and ambient environment can all have an impact on the optimum oil choice. When all of these "old" cars were not so old, it was common to use 10w 30 or 10w 40 oil in V8 engines, and as I recall that's most of what you would see in auto parts stores...at least around here in the upper Midwest. Maybe something lighter in 6 or 4 cylinder car engines (though some motorcyclists would use heavier oil.)

Some folks today will use the 15w 40 and heavier in old engines like the Ford FE or Y Block to help bolster declining oil pressure associated with worn contact surfaces (though not everyone using heavy oil is doing it for those reasons.) I've heard different opinions on taking that approach, but it does work in that context. I have some 15w 40 Rotella in my Y block right now. I'd bought a bunch of that stuff a while back so I'm just using it up. When I use oil that heavy, It's my personal policy to not start the car in the winter unless the ambient temp is 40 deg. F or higher (since it's stored in unheated spaces.) The engine is original and not rebuilt, but the pressure is high enough when hot (close to 20 at idle, maybe 45+ on the highway) that I can go to a 10w 40. That's what I'll use when the heavier oil is used up. The only reason I used the heavy Rotella to begin with was because they were putting ZDDP in it (at the time.)

OTOH, the FE in my T-Bird seems to be rebuilt with a high volume oil pump, so I use a 10w 30 at the recommendation of a local engine rebuilder/expert. I also use STP treatment in the blue bottle, but there are as many opinions on additives as there are on oil. Aside from STP, I generally stay away from most oil additives, but on rare occasion will use Sea Foam (only on a as needed basis to free sticky rings.)