Anyone Using 5W-30 Oil? Tell Me your Opinion/Thoughts

[ChrisNLA]

I'm running 0W-20 because the cap says so. I have too many other things to worry about than second guessing the engineers.

I have deviated on two vehicles we own:

My '93 Chevrolet C1500 with a 5.3L LS Swap - I've been dumping 15W40 in it for a while because I was getting it for free, and its an old project truck that doesn't have 500 miles a year put on it, and I just don't care. It kills batteries and ruins tires from sitting up so much.

Our '06 Chrysler Town & Country - it calls for 5W-20, but I've been putting 5W-30 in it as that is what my 2015 SS Camaro calls for and doing that limits the amount of different oils I need to buy, and I put the 'suggested oil' in the most expensive engine I own. The 5W-30 also works fine in our John Deere riding mower.

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[Hootbro]

Got to love a good oil thread.

A few years ago before I bought my 3rd Gen Colorado ZR2 I did a fair bit of research on the 2.7L TurboMax. That included watching a few interviews with one of the GM engine design engineers on that project. Here are some comments he made during one of the interviews. "We architected the engine to run on 0w-20", "We recommend 5w-30 but the engine was actually architected for 0w-20". And, "Provides more resistance/capability for the bearings". I thought that was very interesting.

In the big scheme of things there is not a heck of a lot of difference between a 20 or 30 weight oil. I doubt anyone is going to hurt the engine with either.

Back in 2015, RAM launched the truck version of the 6.4 HEMI for their 2500/3500 trucks. On the RAM Youtube page back then there was a Q&A video with the RAM division President and RAM Chief Engineer and the question was asked if 0W-40 was actually required (?) as that was the only grade called out in the RAM owners manual for the engine. The reply back straight out the RAM Chief Engineer’s mouth was “no, all engine testing to include tow certification was done with 5W-30 MS-6395 spec oil”. No further explanation was given on why 0W-40 was spec’d in the owners manual. Within a year, the video disappeared.

There was a lot of the same “oh noes” of people on the RAM forums about running 5W-30, but the few that did and performed an oil analysis showed no issue with it.

Somewhat of a reverse issue of going from a called out heavier grade to a thinner grade but the main angst was the 0W-40 MS-1633 SRT oil spec was hard to find and expensive with Pennzoil and MOPAR being the only one for the longest time.

 

[NortonJTSS]

Will 35s fit?

What should I name mine?

 

[JTGuy]

If the difference between 0-20 and 5-30 makes the difference between running and failing we got a bigger problem. No matter what oil is specified there will be those that know better and say something else is better. I have 4.88s and 37s so I wonder what oil is best. LOL. how about an oil for my trans reverse clunk.

 

[ShadowsPapa]

If the difference between 0-20 and 5-30 makes the difference between running and failing we got a bigger problem. No matter what oil is specified there will be those that know better and say something else is better. I have 4.88s and 37s so I wonder what oil is best. LOL. how about an oil for my trans reverse clunk.

the irony is - it's being done "just because" of old beliefs, and so on - and in a few cases, it comes across as only a fool would follow the book or worse - sort of a "right of passage". Hey, I'm running heavier oil like the big kids do. .Sometimes a response might be - so, do you want a bone or a biscuit?

There's no real data either way. (other than the millions on the road that don't have issues and have always run the recommended oil).
Further - you can find instances of cam failure when the owner ran the heavier oil.
So either it didn't solve anything, or they used an oil with less WEAR PROTECTION.

 

[Lost1wing]

5w30 has been worked well in my other engines that call for 0w20. That is hundreds of thousands of miles. I still use 0w20 in the JT however. I'm thinking about using 5w30 when I run out of 0w20.

From what I have read, heavy oil can be used for a longer period of time and for more hours of operation.

The light weight oil will work better in colder climates. It loses it's lubrication and corrosive properties sooner than a heavier weight oil.

My conclusion is that if you live in a colder climate stick with the lighter oil and be sure to change it at or before 5k miles.

If you live in warmer climates, it doesn't matter. Still change the lighter weight oil at or before 5k miles.

I think anyone who has put an oil in their engine that is not the recommended oil weight, has already done their research.

My idea of going to 5w30 is to keep it silly simple. I want to have one oil for all of my gas engines.

 

[smlobx]

Just some basic science to add to the discussion. In general…

0WXX is tested for cold cranking at -35C (-31F) and for pumpability at -40C (-40F).
5WXX is tested for cold cranking at -30C (-22F) and for pumpability at -35C (-31F).

This means that for the vast majority of us a 5W will be fine. So will a 0W but unless you live in the extreme northern part of the US or Canada a 5W will be fine.

Also, the speed that the oil gets into the various galleries in the engine is directly linked to the speed of the oil pump not the weight of the oil. The galleries will fill in a cold engine just as fast with a 0W-20 as a 5W-30.

 

[smlobx]

Another thing to consider is that oil is, according to AI, between one and two nanometers long …or in other terms about 50,000 times smaller than a human hair cell. …

 

[ShadowsPapa]

From what I have read, heavy oil can be used for a longer period of time and for more hours of operation.

The light weight oil will work better in colder climates. It loses it's lubrication and corrosive properties sooner than a heavier weight oil.

Where's that come from?

Corrosion inhibitive nature or ability is chemistry, not viscosity.
Light oil loses lubricating abilities faster? Maybe with heat, but not time.
Heavier oil isn't going to "last longer".


From BITOG blog:

The multifaceted report....funded by GM and several major oil companies and published years ago in the SAE journal (sadly, you need to be a member to read) noted that:

The pistons/cylinders are only lubricated by oil that flys offs the rod bearings and the tiny squirter hole on the rods. The crankshaft oil is fed from the mains, though the crank, then into the rod bearings....by then under almost no pressure and no flow when thick and cold....the end result is only one drop every few seconds flying up to the cylinder/piston interface. Later, when the oil is hot and thin this is a continuous shower of oil. The conclusion of this study was related to the switch from 10W30 to 5W30.....and that many typical driving profiles that this alone would increase engine life by 30 percent. Data was reinforced by multiple testing procedures, including pistons, rings and sleeves using various radioactive isotopes and running instant real time wear measurements. The first few minutes of operation cause more wear then the next hour!

From AMSOIL -

Thicker Oil May Not Flow Quickly Enough
In Brad’s case, his 15W-50 racing oil may be too thick to flow quickly enough to fill the spaces between the crank journals and main bearings while the engine is running.

The oil won’t form a consistent lubricating film, allowing metal-to-metal contact and wear. His engine was designed specifically to use a lower-viscosity oil, in this case 0W-20. Its lower viscosity allows it to flow faster and fill the tiny clearances between parts, leading to a durable, consistent lubricating film.

Not only that, but the engine will waste energy pumping the thicker oil, reducing fuel economy. Since thicker oil doesn’t transfer heat as well as thinner oil, operating temperatures will increase, possibly leading to accelerated chemical break down (called “oxidation“) and harmful sludge and deposits.

For a deeper dive on oil viscosity, check out this post.

Some Oil Viscosity Differences are Less Pronounced
In John’s case, using 10W-30 instead of 5W-30 creates fewer potential issues.

His older engine isn’t built with the same tight tolerances as Brad’s engine. Also, both oils are the same viscosity once the engine has reached operating temperature. He knows this because the second number in each oil’s viscosity rating (i.e. “30”) is the same. It describes the oil’s resistance to flow at 212°F (100°C), or normal operating temperature.

 

[Lost1wing]

I read that in a machining article. The topic was oil temperature comparisons at start up and after warm up.
The thinner oil did a better job of cooling but required to be changed out due to the loss of protection from wear and corrosion inhibitor evaporation.
They also mentioned the auto industry going to lighter weight oils as low as 8 weight.

 

[ShadowsPapa]

I read that in a machining article. The topic was oil temperature comparisons at start up and after warm up.
The thinner oil did a better job of cooling but required to be changed out due to the loss of protection from wear and corrosion inhibitor evaporation.
They also mentioned the auto industry going to lighter weight oils as low as 8 weight.

And yet oil analysis from real engines using our oil state they are still good - even hearing it from Lake himself....
I'd suggest that unless you run severe conditions, or want to go over 10k miles it's just not even close to any issue.
How far out were they taking that oil- 15,000 miles??

 

[Stan H]

Even Lake basically keeps suggesting that................. but there are plenty of engineers that know better (on forums everywhere) and keep thinking that thicker is better.


Have to laugh about the extreme change from 20 to 40 as it's a given, proven, even, with tests on real engines, that jumping that much leads to hotter oil, and hotter engine parts - and then they complain about engine heat. Uh, they cause their own problems.

From those oil engineers -

it's crucial to use the correct viscosity for the application, as too-high viscosity can cause other issues like increased drag and heat.

So you believe ithe engineers haven't worked to make the oil and engines work together...................

I say we skip engineers and just go straight to straight 60W oil . That ought to quiet something down .

 

[Stan H]

OMG - that "we need more zinc" crap. That's so 1980s - it's been shown by university tests as well as others, more is not better, more can actually cause wear, zinc stops building on things and starts causing damage if too much is used, and today's oils have chemistry that negates the need for high zinc.
Zinc can also actually cause damage to the castings in engines.
If you use a quality oil - zinc is of no concern.

I have Comp Xtreme cams in both of my cars, had one in my 70 390, and I used off-the-shelf oil, good oil, no additives at all. I've never lost a cam in any engine I've built. Heck, my 4.0 with the Comp Xtreme energy cam is running stiffer valve springs, higher compression and so on - put it in the car, started it, drove it - all with the same oil I'm running in it now years later. Nothing special.

With modern oils, it's not even necessary in the older stuff. But people are still freaking out over the failures from the 1990s or so when there was that transition period and yeah, there were more failures back then.

That made me chuckle haven't you heard retro is all the rage.

 

[Stan H]

What should I name mine?

Nightmare !!! Cause its a scary ride !

 

[bgott]

I say we skip engineers and just go straight to straight 60W oil . That ought to quiet something down .

Used to be able to buy 70 wt. Kendall GT off the shelf.

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