5.7nhigh millage what oil do you use?

[Hunter79764]

I'm not a fan of the "High Mileage" oil. Everyone I know that has switched has noticed increased oil consumption, and sometimes it doesn't always get back to normal after going back to the regular stuff. Maybe it's coincidence, but I've seen it at least a half dozen times among family and friends.

I'd say use whatever the manual or engine builder calls for (up to using the "hot climate" oil even if you are in a mild climate) until you are seeing real oil pressure issues, then switch to a step heavier until you can get a rebuild figured out. Thicker oil for a car with low oil pressure is a bandaid. You don't know where those loose clearances are that "need" thicker oil, and you are trying to push that thicker oil everywhere else that is still fairly tight clearance.

I've heard mixed opinions on the ATF issue. From some knowledgable folks, the basic idea is that half a quart of ATF is unlikely to dilute the lubricating properties of the rest of the oil, but the detergent pack in ATF is meant to be MUCH longer lasting than the detergents in engine oil, and act in a different way that might help clean some sludge.
I prefer SeaFoam or Marvel Mystery Oil (which might just be modified transmission fluid?) before an oil change, although SeaFoam in the intake is the better use to me. Just notify the neighbors ahead of time, you don't want the fire department showing up

 

[Ifyasquintitsmint]

Walmart brand if I don't care about the engine. Liqui moly if I care about the engine.

 

[SirRobyn0]

I’ll assume you posted this in jest. For the rest of the crowd, while ATF may work in transmissions and transfer cases and serve as a good injector cleaner for old diesels, there is no plausible reason to add any to ANY engine’s motor oil. Unless your goal is to turn good oil into bad and wear out the engine quicker.

I think this is a carry over from back in the days when engine oil was non-detergent or not nearly as good of detergents as we have today. But for like the last 40 years or so I'd say this is a bad idea.

 

[SirRobyn0]

A good "heavy duty" or diesel 15W40 is great in a high mile motor with flat tappets since it is a little higher in zinc, and is what I like to run.

 

[SquareRoot]

 

[Ricko1966]

Atf is oil,I forget the weight,with friction modifiers,red dye,and lots of detergent.I've used it for decades just like other people use seafoam,stp, crc,etc. It's an old trick for cleaning up sticking lifters.

 

[Catbox]

Usually the house brand or what's on sale.
It is slippery and does a good enough job that my lifters aren't wiped out yet.

When I switch to a roller lifter engine, I will still use the house brand.
Easy peasy.

 

[SirRobyn0]

Atf is oil,I forget the weight,with friction modifiers,red dye,and lots of detergent.I've used it for decades just like other people use seafoam,stp, crc,etc. It's an old trick for cleaning up sticking lifters.

I don't disagree with what you are saying, running it in a neglected engine to clean it out. But I do not think a person is doing any good substituting a 1/2 quart or more of oil at every change. All a person is doing is thinning out the additives designed to be there.

 

[GTX63]

When I bring a high mileage squarebody home, or get one that has been sitting for an extended period, I use 15 W 40. The oil in the ground hasn't changed, but the refining has. The old flat tappet Chevy is the same; newer modern engines are not. Different metals, tolerances and requirements. I may also use additives to bring back the rings and valves, etc. After they are on the road and running, I continue to use 15 W 40. It is preference. Gen 1 SBC are not suddenly spitting rod caps and spraying oil out the tailpipe for using a specific lubricant. I know what happens when running mobile 1 in a tired 307, but I'm being inclusive here.
My opinion is based on my experience, and not the be all to everyone else. I'm not telling anyone they are wrong, rather what works for me.

 

[Buicknut]

I plan to run Brad Penn oil in mine.

 

[JT58]

The shop that did my rear main and replaced the oil pan on my 87 with a 74 5.7 in it used 20W-50. Hot climate here in So FL. most of the year. A very few days with 50-60 at the coldest. Seems to run good with the 20W-50 in it. I was wondering what oil to use also going forward. Truck has a good rebuilt engine, no smoke and uses no oil at all. Would 10W-40 be better or continue to use 20W-50 with the warm climate?

 

[Ricko1966]

Use factory recommended oil, as long as you aren't having an oil pressure problem all the thicker oil does is cost you horsepower and mpg. If you are having an oil pressure problem the thicker oil is just masking the real problem. If there were a need for a different oil in Florida GM would have come out with a bulletin run x oil except for Florida residents who should run y oil.

 

[Ricko1966]

For you brand loyal enthusiasts,In reality most of the oil brands are the same just in different jugs. I found this out by accident, I called one of the oil company tech lines back when losing the dzzp became became public knowledge. I was paranoid about the 66 Chevelle so I called I think it was Valvoline to ask about their racing oil, the guy answered with. I think it was Castrol how can I help you. I was like I was calling Valvoline, he said yea we are all the same company, end of conversation was run 15w40 rotella t4 it is still full of dzzp, ignore that it says diesel on the label.

 

[TotalyHucked]

For just an ole small block? Whatever is cheapest in either 10W30 or 15W40. Rotella if it's a great running engine, if it's tired, whatever is cheapest. Old engines don't care too much what you run lol

 

[84GMCSierra]

This is what Easton uses. He follows Derek from Vice Grip Garage so that’s where he came up with the choice. I think he adds some Lucas oil additive of some type as well.

That's what I use. Our Walmart doesn't carry conventional oil in quarts, only semi and full synthetic, but they have this.