Is 10W30 oil hard to find where you are?

[66 Monaco 500 365]

I wanted to add a thought, 5W30 is the same viscosity (the 30 part) when the motor is up to temp, it is a good substitute for 10W30
My $.02

 

[70NEWYORKER]

Very hard to find 10W30 conventional at the discount stores around here. Everything is a straight synthetic or blend. Parts stores still seem the have it, but that gets mighty pricey.
Conventional oils have a shelf life of about 6 months(per phone conversation I had with a chemical engineer at Chrysler Corp in the late 90'S). Stockpiling conventional oil where to additives will precipitate out over time and then get run through the crankcase with unknown effects or run synthetic and leak like a SOB....living in the future really sucks.

 

[66furys]

Interesting that back in the day of some of our cars.....there was no multi vis.....it was 30wt. And then, the boys decided, about 25 years ago, that the catastophic converters do not like the ZDDP that comes with burning oils, so they dumped it. The way back then was to look for the EPA star on the can. They have not done so with the diesel oils. So, for the flat tappet crowd, you are missing the good stuff that lubes the flat stuff, that is the four ball test by ASTM.....the high wear places that have been designed out of modern engines, mostly with roller lifters. But, for the lawn mower and our old camshafts, you need to add ZDDP. And, the oil pressure is added to the rotating journal with a given clearance. This clearance creates the hydro film for bearing load carrying. And, that clearance is what determines what visc oil you require. Old stuff had larger clearances. So, what you may find is that for our new thinner vis oils, your pressure is down a bit. I like the diesel oils, that have NOW been thinned too, from the old std of 15-40 to 5-40. Now out of the design world, I have not looked at the viscosities of the different lubes for a while....but my bet is that for the normal range of about 200-275 F, our new stuff is thinner....just a guess. But, I often will use the diesel oil that was more viscous, and had the additives. Yes, some will say, the package is different between the gas and diesel oil. But, the good parts like detergents are present, etc. Also agree.....diesel oil not for racing.....maybe.

 

[MoPar~Man]

Oil (even conventional) better not have a shelf life of 6 months - or I've got 10 gallons of oil to get rid of. Even pump gas should last 6 months in the tank.

I've just had a look through a few dozen pages of posts on BITOG on the subject. There are a lot of guys there that know a lot about the chemistry of oil. The general idea I get is:

- if the oil has been stored in sealed containers, indoors (ie not subject to ambient temperatures, not stored near a boiler or furnace either)
- if the oil is not unusually thick or contains solids
- doesn't have an unusual smell

Then the shelf life is indefinite. A lot of them balk at the idea of oil, synthetic or not, having a shelf life. They say that manufacturer's labelling a shelf life on the side of a jug is for marketing / turnover.

Lots of them claim to have and use very old oil, (decades old) in this or that particular vehicle without issue. The ancedotal stories like that would quickly "flush out" observations like "Hey, I just opened some of my 15 year old stash of XYZ and wow, did it stink and turn chunky". I see no stories like that.

I don't believe I've come across anything specific on BITOG that explains why theoretically conventional oil would have a reduced shelf life vs synthetic either, but maybe that specific question wasn't asked.

 

[70bigblockdodge]

I wanted to add a thought, 5W30 is the same viscosity (the 30 part) when the motor is up to temp, it is a good substitute for 10W30
My $.02

This is a good point. The first number is it's cold weather flow characteristics (how fast it gets around at first start) the second number is the protection weight/value at temp. This is why all the zeroW whatever you see in synthetic oil. You also need to look at the major use of the car. Short trips of 15 minutes of run time or less could benefit from a 5W30 instead of 15W40, a word of caution is old cars contaminate oil faster due to choke and carburetor inaccuracies, fuel injection is cleaner quicker and adjust all the time, keeping oil cleaner.
Oil changes are always important.

 

[DusterKid]

10w30 still somewhat easy for me to find. 20w50 not so much.

 

[Gerald Morris]

I've been ordering 6 qt "box wine" containers of venerable old Havoline 10W-30 from Walmart for Gertrude's 383, then adding a pt of Lucas ZDDP to 4.5 qts oil. Wallywurld sells these boxes for $19.99, which is a damn good price. Who remember's when Bob Hope pitched Havoline for Texaco? It's a good oil. Chevron usually sells its own name brand, but apparently, having gobbled Texaco, keeps their refineries running.

I decided to try Quaker State synthetic in our /6 83 Dodge D150, as it has a damn cat on the pipe, so I'm not pouring on the zinc. Maybe if I can "improve" that cat, I can then go back to conventional. Am considering Royal Purple for that motor. My old Mopar mentor, deceased now a decade used to swear by that brand for ALL his Mopars.

 

[1966newport]

most 10w30 on self wont have enough zddp

 

[MoPar~Man]

Castrol GTX Classic 20W-50 (conventional) Specialized additives containing high Zinc (1400 PPM Max) and Phosphorus for extreme wear protection.

Is 20W50 too far outside the box for our engines? Small block also?

 

[66furys]

20w 50 is used a lot for motorcycles, esp HD that does not use conventional bearings, and is also used for the hydro trans systems.....not sure why some specify a motor oil in lieu of the hydraulic oil.....way different specs. But, in my humble world, prob too heavy for normal lube of your crank. Again, all revolves around viscosity to enter and build the film and flow thru to cool. On some large gears, they use a bubbler on the top of the bearing that allows some of the exiting oil to flow up into a visible bubbler that shows flow and measures temp. You can easily tell if things are right with the two factors. And hell, you have to remember that on our crankshafts, not the russian design, that oil must flow out of the main journal....with its pressure thru a long hole to feed the rod journal. This is why the rod is always the weak point.....lube. So, likely you will be reducing that flow to the rods that is so critical and will not even know it with the real heavy stuff. In some race engines they purposely build in very large clearances for friction reduction, esp since they will op at high rpm. This can then affect the type of lube they will use. Lastly, to get a feel for it, just pour out a spoonful of the 50w....it is pretty thick stuff.....I have a lot on the shelf for the other apps.

 

[73Coupe]

The more I research, the more I think that the assumption of needing a higher concentration of ZDDP is a little overrated for older engines. Every engine is different though. Only way to tell is with empirical data. Send in your oil sample to Blackstone labs. Do it with and without ZDDP additive and compare the amount of iron, lead, aluminum, or other concentrations of engine parts metal in the oil. I did this a few years ago and made no difference.

 

[66furys]

Actual test data is the best....get er dun. I am old, and the old guys that taught me thought that we needed the additives in the oil, for various things. And when the conservators took out some of them....I got nervous, so I add back the old stuff, for grins. But, it may not be as necessary as the old guys thought. Too bad some of the so-called scientists today do not actually rely on empirical data....because if you dont collect it, you cant analyze it. Keep up the good work.

 

[Gerald Morris]

Castrol GTX Classic 20W-50 (conventional) Specialized additives containing high Zinc (1400 PPM Max) and Phosphorus for extreme wear protection.

Is 20W50 too far outside the box for our engines?

Castrol GTX Classic 20W-50 (conventional) Specialized additives containing high Zinc (1400 PPM Max) and Phosphorus for extreme wear protection.

Is 20W50 too far outside the box for our engines? Small block also?

Our engines were designed with 10W-30 in mind. Here's Chrysler's instructions from the 1966 FSM, C-2 "Lubrication" p1, Col 1:

This remained fairly standard for Mopar engines for some time. As late as 1983, 10W-30 still was the factory oil. Here's a chart for my 83 Dodge D150, w a 225 /6:

The new 4 cylinder engines most often warranted the high viscosity stuff by then. Note how 5W oils were strictly for cold weather. I'll stick w 10W-30 w a bit of ZDDP for this old engine. After 6 years of VERY harsh abuse w me driving it in city traffic, summer and winter, the original cam, aged 54 years last October, was still sound.

 

[MoPar~Man]

I for one don't really anticipate ever driving my car when it's at the uncivilized temperature of 32f or below. The "20W20" oil type is - interesting. How is that not just a straight 20? And note that that chart does anticipate the existence of a 20W50 (was that type around years ago?). A 20W40 would seem to be ideal even for most of us in the northern latitudes. ?

Why would a 5W30 or 5W40 have an upper cut-off at 60F but a 10W anything is good to 100?

 

[Gerald Morris]

Actual test data is the best....get er dun. I am old, and the old guys that taught me thought that we needed the additives in the oil, for various things. And when the conservators took out some of them....I got nervous, so I add back the old stuff, for grins. But, it may not be as necessary as the old guys thought. Too bad some of the so-called scientists today do not actually rely on empirical data....because if you dont collect it, you cant analyze it. Keep up the good work.

I use data from the PQIA. Here's a report from 2021 on the stuff I run. Was happy to see that it has 996 ppm Zn off the shelf. Havoline is a good Old School oil.

Chevron Havoline SAE 10W-30 Motor Oil | The Petroleum Quality Institute of America

 

[MoPar~Man]

So explain this to me. I remember adjusting valve lash on my '65 polara with slant-6. Is that a flat tappet? Did any of these v8's have hydraulic lifters? Or can you have hydraulic lifters and flat tappets? Roller cams? Which of all those needs additives like zinc the most (or least)?

And while were at it, hardened valve seats for unleaded gas? What production years would that have been a concern? I remember taking my /6 head to a place in Detroit to get the seats induction hardened when unleaded gas became unavailable (1984-ish).

 

[66furys]

The flat tappet means that the bottom of the tappet just rides on the cam. It does so just offset a bit so that it will turn for even wear. But, the flat tappet is either solid or has the internal hyd adjuster. And, as for the argument on oils, many folks have found that there aint much wear on the valve seats after all. I have seen some evidence of recession....photos of the wear. But also lots of reports of no problemo.....so not sure panty bunching required here. I recently had a ford flathead machined and decided not to add seats. Just me. And, I see that Gerald has too much time on his hands....just kidding. Good research.

 

[RWCearley]

My 1970 nova with a 307 had problems when lead was removed from gasoline. A valve job would only last about 20k miles. Valve recession was the problem. Switched to 1975 chevy 305 heads with stelite seats. Problem solved.

I add ZDDP to my crankcase with every oil change. I too have heard that it is not necessary. I know that zinc was removed because of problems with catalytic converters and was no longer necessary since flat tappets were replaced with roller rockers and tappets. That said, ZDDP is cheap insurance for our vintage autos.

 

[Gerald Morris]

So explain this to me. I remember adjusting valve lash on my '65 polara with slant-6. Is that a flat tappet? Did any of these v8's have hydraulic lifters? Or can you have hydraulic lifters and flat tappets? Roller cams? Which of all those needs additives like zinc the most (or least)?

And while were at it, hardened valve seats for unleaded gas? What production years would that have been a concern? I remember taking my /6 head to a place in Detroit to get the seats induction hardened when unleaded gas became unavailable (1984-ish).

ALL of these Venerable Mopar Motors were flat tappet, as that was all that was available for cheap mass production Back in The Day. The V8s had hydraulic lifters from LOOOONNNNGGGG ago, I think, Day One for the B/RB blocks. You can read up at Allpar for that lore.

Roller cams/lifters/rockers DON'T NEED ZDDP! That in fact was the impetus for their development, with the damned cat converters making zinc and lead prohibitive. (Both will trash the converter, filling it with metal deposits until it plugs the exhaust. I stupidly did this long ago as a Teeny Weeny w a 76 Chebbie Nogo) From the mid 1970s onward, valve seats got hardened in production. The 452 heads, open quench, high flow heads based on the 906 design became standard for the Formals and mid-late 70s "smogger" B/RB engines. I have a pair, which came w our 400.

Cold weather zapped oil pickup and pump priming this morning on Gertrude, so I must crawl under a ton or so of iron propped over my head. I PRAY that's all that caused this major mischief! Noticed even the /6 took some time to get oil pressure up good when I warmed IT up. The Torture Never Stops here....