edyvw
$50 site donor 2026
I am not sure how that answers my question, but ok.
Little experiment....Going from 5W30 to 5W40
- Thread starter mrgto
- Start date
edyvw
$50 site donor 2026
Absolutely serious. Please explain to us who don’t know.
You may or may not gain anything moving to a 5w40. Won't hurt though. Could take a small hit in fuel economy. Without knowing the condition of the engine in terms of wear, impossible to know what viscosity is most ideal. Could be a 30 grade or may require a 40 at this stage of its life. UOA would give you some baseline.
It's well-known fact often mentioned in the used oil analysis section, where those with experience notice slightly higher concentrations of some measured values specifically due to the PREVIOUS oil used. Molybdenum is a good example: an oil with NO molybdenum in a virgin sample will show a significant concentration of it when the previous oil had a significant molybdenum component. If you wanted to do the math, you could determine the volume of oil retained during an oil change. Therefore, the recommendation is often to wait until further intervals to obtain a sample as those subsequent values will be further diluted. Same as for whenever there is a spike in Silicon due to a sealant used in a repair or dust ingress from a leak in the air filtering system...the Silicon from the repair or dust gets diluted with the new oil, and the detected silicone will gradually decrease over time. Different engine designs have varying volumes of retained oil during an oil change. Some engines even have multiple sites where you must drain each site to get the majority of oil changed. It also depends upon WHEN you change the oil and how long it drains...and was it a hot or cold drain? You can find the volume of expected retained oil by comparing "dry fill volume" (new engine) to "oil change volume".
The ambient temperature - in South Florida is not as hot, BTW - has no bearing in determining oil viscosity. It only affects the winter rating selection.
The hottest temperature ever recorded in Death Valley (134F) cools down the engine oil.
Try reading more and posting less.
edyvw
$50 site donor 2026
So you found the need to give "answer" to a question I did not ask, so you can feel better about yourself?
What else is going on in your life that needs intervention? Maybe we can help here.
Even of you do see different results there is no way to correlate that to the oil. You can’t use random spectrographic analyses to perform comparative quality analysis between two oils. It would be only an imaginary result.
1st drive today. Might be my imagination but the engine sounded quieter at start up and after a drive to the store. Maybe I should have had a video of before and after. I think I probably do have some timing chain slap(it's not horrible) and that seemed to have gone away. I'll keep an eye on the fuel economy to see if it goes down at all.
Hmmmm
The differences in the owners manuals of the different continents, to your point do have to do with CAFE....but, ambient temps absolutely effect the preferred viscosity per the engine, in cold and hot. This is a screenshot of a 6.2 GM Diesel, from about 45 years ago.
Known then.....now you know.
A lower viscosity at start up (cold) will always sound quieter, quicker flow to engine components, as much of engine wear can occur at this time. Anti-wear additives also play a positive role at starting.
edyvw
$50 site donor 2026
Hmmm, yes, 45 years ago, when cooling technology was different, and oils were definitely different.Hmmmm
The differences in the owners manuals of the different continents, to your point do have to do with CAFE....but, ambient temps absolutely effect the preferred viscosity per the engine, in cold and hot. This is a screenshot of a 6.2 GM Diesel, from about 45 years ago.
Known then.....now you know.View attachment 339272
The last 20 years or more are absolutely irrelevant.
dnewton3
Staff member
OP -
You do not have enough data to make any manner of credible decision regarding comparing/contrasting UOA results of the lubes you've used and are considering. Not anywhere close to enough data. Not by a long shot.
Read this: https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
What you can do is look at your data and how it relates to macro data, but even then this is only valid if you have accurate macro data for your engine series in similar applications.
You do not have enough data to make any manner of credible decision regarding comparing/contrasting UOA results of the lubes you've used and are considering. Not anywhere close to enough data. Not by a long shot.
Read this: https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
What you can do is look at your data and how it relates to macro data, but even then this is only valid if you have accurate macro data for your engine series in similar applications.
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edyvw
$50 site donor 2026
Really? Let us know how that works on new GM diesels with electric thermostats, a heat exchanger in addition to the radiator oil cooler(s).
Oils different sure, cooling systems, nah. Same old thing, pump, radiator, fan, recirc.
One thing is for sure, back then, air density in FL was the same as today.
Who is us? I am replying to you. You are always saying "us". Are you in a gang?
Electronic thermostat is a thermostat, it opens when it is told to. Heat exchanger? Radiator oil cooler? Both of those are new ideas....nah .......the truck I cited earlier with the screenshot is a 1986, with a giant radiator, 8 blade fan, engine oil and transmission fluid coolers in the radiator.
edyvw
$50 site donor 2026
So GM couldn’t maintain oil temperature through cooling system. I mean it is GM.
Who is us? I am replying to you. You are always saying "us". Are you in a gang?
Electronic thermostat is a thermostat, it opens when it is told to. Heat exchanger? Radiator oil cooler? Both of those are new ideas....nah .......the truck I cited earlier with the screenshot is a 1986, with a giant radiator, 8 blade fan, engine oil and transmission fluid coolers in the radiator.
His cooling system will maintain the oil temperature. It is Florida. Air density is high.
Electric thermostats are not stuck on minimum temperature to open. They can open on demand. For a very good reason.
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Far better? I doubt it. The difference in oil temp with ambient temperature is not massive.Pennzoil Platinum Euro 5W-40 is a heavyweight, HTHS ~ 3.8'ish.
Far better lube than the Valvoline Restore and Protect in your Florida heat.
Good move
Platinum Euro is very good oil and I’d run it with confidence. Heck, I think Ferrari specs it (as Helix Ultra) in some cases.
But it’s almost certainly not “far better “ than the flagship Valvoline product and certainly not due to Florida heat.
As I said, the manual recommendation is base on CAFE requirements. Ambient temps can affect recommended viscosity choices...if not for CAFE... and those alternatives could be included in the manual. However, CAFE language doesn't mean a passenger car operated in usual fashion will be damaged by the CAFE recommendation of a well-formulated 0w20 even in "hot temperatures". That said, I run Mobil 1 ESP 0w30 in three vehicles that spec 0w20 because I prefer using oil with a higher HTHS compared to the theoretical tiny increase in fuel efficiency of 0w20. Altitude affects viscosity choice even more-so than ambient temps due to less dense air providing less cooling effect at elevation...I'd be more concerned about using a higher viscosity during high mountain driving than with humid-and-warm Florida climates. Florida really isn't all that hot compared to the desert Southwest...and there are some high mountains out there as well. Florida climate is a walk-in-the-park in comparison.Hmmmm
The differences in the owners manuals of the different continents, to your point do have to do with CAFE....but, ambient temps absolutely effect the preferred viscosity per the engine, in cold and hot. This is a screenshot of a 6.2 GM Diesel, from about 45 years ago.
Known then.....now you know.
