Valvoline 15W-40 diesel engine oil

[Rockinindian]

Bob what's your opinion on valvoline 15W40 diesel engine oil?
I saw a video bad mouthing it breaking down under high heat or heavy loads . The video was not trying to sell or recommend their brand or a certain brand of oil.

 

[Plumb Bob]

As good as the approvals they carry. The Premium Blue line is "good stuff".

 

[JavierH19]

Which one, they have several variations. But all in all I'd happily use the lowest tier one as none are really bad.

 

[fantastic]

Bob what's your opinion on valvoline 15W40 diesel engine oil?
I saw a video bad mouthing it breaking down under high heat or heavy loads . The video was not trying to sell or recommend their brand or a certain brand of oil.

What is the value of this YT opinion? I can find just about anything on YT. A bunch of it is & YT algorithm seems to push what charges peoples emotions to get more $$ in add revenue.

 

[Rockinindian]

What is the value of this YT opinion? I can find just about anything on YT. A bunch of it is & YT algorithm seems to push what charges peoples emotions to get more $$ in add revenue.

The internet is not what it used to be, it's all sell sell sell ads. I rely on AI for answers but it also lies

 

[53' Stude]

Bob what's your opinion on valvoline 15W40 diesel engine oil?
I saw a video bad mouthing it breaking down under high heat or heavy loads . The video was not trying to sell or recommend their brand or a certain brand of oil.

I like their Maxlife 15w-40. Still have tons from the clearances. The white jug 15w-40 is good. Please don’t believe in all the lies about oil on the internet. Plenty of folks here that know way more than you and I about oils.

 

[carl2591]

I think in teh end what matters is the API certs the oil carries.. for diesel engine teh CK-4 and CJ-4 tend the be the overbest oil for the more late model engines, with or with out emissions.. more so for truck with emission in helping to protect the DPF etc. the weight is the main concern for some engines.. for ram the 2019 and up truck are recommend a 10w30 or 5w30 depending on temp you normal encounter.. for other engines that seem to be constant as well..

Cummins pre 2019 15w40 or 5w40 is the preferred juice again depending on temp you encounter on the normal..

the biggest issues if dino or synthetic oil. Valvoline did a test on two cars running one with 5w-30 dino and the other a synthetic oil putting some 1 million miles? i believe on them.. upon tear down the biggest difference was the amount of varnish on the interior.. with the synthetic being the more clean looking of the two.. the video show the tear down in real time..

 

[53' Stude]

I think in teh end what matters is the API certs the oil carries.. for diesel engine teh CK-4 and CJ-4 tend the be the overbest oil for the more late model engines, with or with out emissions.. more so for truck with emission in helping to protect the DPF etc. the weight is the main concern for some engines.. for ram the 2019 and up truck are recommend a 10w30 or 5w30 depending on temp you normal encounter.. for other engines that seem to be constant as well..

Cummins pre 2019 15w40 or 5w40 is the preferred juice again depending on temp you encounter on the normal..

the biggest issues if dino or synthetic oil. Valvoline did a test on two cars running one with 5w-30 dino and the other a synthetic oil putting some 1 million miles? i believe on them.. upon tear down the biggest difference was the amount of varnish on the interior.. with the synthetic being the more clean looking of the two.. the video show the tear down in real time..

Just another great reason why I don’t believe Whats on YouTube. Many folks here ran a conventional/blend to 10k and beyond with zero issues.

 

[carl2591]

Just another great reason why I don’t believe Whats on YouTube. Many folks here ran a conventional/blend to 10k and beyond with zero issues.

trying to figure what not to believe on the video.. both oils did a fine job in the engines, that's not the issue.. the biggest difference was the amount of varnish buildup as you can see in the photo.. engine on left much cleaner looking than engine on right.. seems to me the oil with less varnish build up will be better over all for the engine.. here is what AI was showing on engine varnish.. to me it looks like the synthetic oil is a win for the engine..

What would be super interesting would be to have the two engines reassembled and run with the valvoline restore and protect oil for say 50K miles and pulled down to see the cleaning effects of the oil.. several including me suggested that on the comments of that video.. will they do it ,, who knows.. but man that would be fricken awsume..

<<<<<<<<<>>>>>>>>>>
Effects of Engine Varnish:

• Reduced Lubrication: Varnish can hinder the flow of oil, leading to inadequate lubrication of engine parts.
  
  
• Component Wear: The abrasive nature of varnish can cause increased wear on moving parts.
  
  
• Valve Sticking: Varnish can cause valves to stick, leading to poor engine performance.
  
  
• Clogged Filters and Passages: Varnish buildup can restrict oil flow, potentially clogging filters and oil passages.
  
  
• Increased Engine Temperatures: Varnish acts as an insulator, trapping heat and potentially leading to higher operating temperatures.
  

 

[Hohn]

As good as the approvals they carry. The Premium Blue line is "good stuff".

As I've mentioned elsewhere, Premium Blue isn't just the Endorsed by Cummins, it is the "house oil" we use for all our engine testing in the USA.

We buy totes because some of the oil pans hold more than a 55 gallon drum

 

[greaseguy15]

Most 15w-40 products in the market can be considered semi-synthetic nowadays. With the tighter spec limits for things like volatility and stay in grade they almost all contain some amount of synthetic. It’s just a marketing decision whether or not to call it one.

 

[johnmyster]

What class/size/application are we looking at? For the most part, today's diesels...

Have big bearings and turn at low RPMS. Also they have oil coolers, so unless you're modified and towing like a bonehead on grades, oil temperatures stay reasonable.

UOAs on this site for PSD/Cummins/Duramax generally reflect that they are not "hard" on oil, especially in the ULSD era. Leaky oil coolers, head gaskets, leaky egr coolers, and fuel dilution are the common threats to lube integrity in 2025 that joe light duty diesel pickup owner should be aware of. Heat and "viscosity breakdown" are non-factors during sane OCIs.

Last I checked, the Volvo (4.5?) cert has a high temperature test component, and every bottle of HDMO on the shelf at walmart carries that cert.