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Valvoline 15w40 or 5w40

105K views 41 replies 14 participants last post by  dozer12216 
#1 ·
i am about due for my first oil change, and i will be using valvoline's premium blue oil. i chose this because my local "small town" napa carries it, and it seems to be a popular choice after researching the forum.

i went in and asked for the 15w40, and they said they suggested the 5w40 synthetic. so, i bought it. after i got home i did some more research and it seems that the 15w40 is more popular. any suggestions?
 
#5 ·
There is no reason to run 15w40 in the summer. For that matter, other than cost, there is no reason NOT to run 5w40 no matter where you are or what season it is (except the arctic during winter, where even thinner oil may be needed).
 
#6 ·
Just run the conventional 15w40 with the big :cbadge: on it and never look back...spend the extra money you saved on your fuel bill,lol
 
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#8 ·
I have ran 5-40 in the 2000 for years. the reason was changing oil at 15-17500 miles with oil analysis occsionally. Now with the 08 and the oil monitor and fuel dilution. I got 8000 miles on oil change before "change Oil" light came on. So the long oil change intervals will not happen, I'll stick with quality dino 15-40 on this one. Well, maybe change mind if delete. Getting over 20 pulling light trailer so can't complain
 
#9 ·
There is no downside to running 5w-40. It is not "thinner" oil. It is thinner at cold temps, but it's viscosity cold is still much higher than when hot. When hot, it has the same viscosity as 15w-40. So, the advantage is faster pumping when cold, with zero downside when hot. So, in fact, 5w-40 is overall better than running 15w-40. Only downside is cost.
 
#13 · (Edited)
There is no downside to running 5w-40. It is not "thinner" oil.
It's thinner at 75*f. Than 10w-40 is.


It is thinner at cold temps, but it's viscosity cold is still much higher than when hot
When hot, it has the same viscosity as 15w-40. So, the advantage is faster pumping when cold, with zero downside when hot. So, in fact, 5w-40 is overall better than running 15w-40. Only downside is cost.
Disadvantage when cold.
A diesel engines puts a heavy load on oil.
Equipment loads must also be considered when selecting the proper lubricant viscosity. Under a heavy load, the lubricant film is squeezed or compressed. Therefore, a higher viscosity lubricant is needed. The higher the viscosity, the more film strength the lubricant will generally possess. In addition, the load can be either a continuous or shock load. A continuous load is a steady load that is maintained while the equipment is operational, while a shock load is a pounding or non-steady load. Under shock-load conditions, a low-viscosity lubricant would not possess enough film strength to stay in place, whereas a high-viscosity lubricant could stay in place and act like a cushion in the contact area.

Shock load in a diesel engine???? pounding??? nooooo...



And a seeing as diesels run at a much lower rpm a low vorticity is not needed.

The speed at which a piece of equipment operates must also be considered when specifying the proper lubricant viscosity. In high-speed equipment, a high-viscosity lubricant will not flow well in the contact zones and will channel out by fast-moving elements of the equipment. On the other hand, low-viscosity lubricant would have too low a viscosity to properly lubricate slow-moving equipment, because it would run right out of the contact zone.

^not good in a cold diesel engine.
Remembera diesel is not a high rpm engine like a gasser is.

info used is from.http://www.bobistheoilguy.com/motor-oil-102/

I think the MFG has it figured out.
but it's your truck do as you wish, use the info and apply it to your needs.
 
#11 ·
Ok, so Cummins/Dodge recommends 15w40 for most of us. So what does everyone prefer as far as brand? Or better yet, rather than start an oil debate, I'll just ask is there anything that I should avoid? I've ran Mobil 1 synthetic for years, but it was because of increased protection and extended oil change intervals.
 
#12 ·
I'm running the Valvoline 15w40 with a Baldwin oil filter. same thing I ran on my '05
 
#15 ·
And you my fellow moron can't comprehend the back of a box of fruit loops.

Now go back and reread my very first line.
"It's thinner at 75*f. Than 10w-40 is."
Whats thinner?
the 5w-40 at 75*f.

The thickness at 212*f is the same. It's not the same when cold.


Next, flow vs psi and the cushion oil provides,
ho wait I covered that with the info from bob's the oil guy.

Then their is the oil recommendation from CUMMINS.
Everyone thinks cummins is all that so why diss the oil recommendation and use a oil that is not the correct weight. You might as well just use conventional oil for a gas engine. or a 0w-20 as it will flow better.:doh:

next, winter vs summer know the difference.


And that Big C on the bottle means that Valvoline won a bid to be Cummings oil suppler.
ALL of the dino oils that are for diesels meet the same qualities as Valvoline.
the big C is marketing towards cummins owners.

5w-40 is winter oil. 15w-40 summer.


this a hoot
"At truly cold temps it gets even worse. The OP lives in North Dakota, where it gets cold in the winter. The 5w-40 has the same viscosity at -30°F (-22°F) as the 15w-40 at only -20°C (-4°F). Likewise, the synthetic 5w-40 still pours down to -39°C (-38.2°F), whereas the non-synthetic 15w-40 is done by -30°C (-22°F). If you live somewhere where it gets really cold, it's a no-brainer."
The only time it has the same vis is after the engine or the oil is up tp 212*F.
When a engine is cold the parts shrink . There are greater tolerances between the parts, a thin oil is not going to give the cushion the parts need. This allows for metal to metal contact.
and again your thin oil at 75*f is not giving the protection you think it is because you say flow is everything and it is not.

It doesn't get any colder in ND than in MN.
-60*f is the coldest each state has recorded.



and guess what sherlock we and a lot of others run 14w-40 year around and guess what those old diesels are still running. and they do start when it cold out.

Remember, the only difference between a 0W-40 and a 10W-40 is that the 0W-40 thickens less after you turn off your engine. It is still too thick in the morning at startup but not as thick as the 10W-40. Yet, they are still too thick to use until they both warm up to operating temperature at which point they have the save viscosity, around 13 to 14. Remember that the 0W-30, 10W-30 and straight 30 grade oils all have a viscosity of around 10 at normal engine operating temperatures. They all thicken when you turn off your engine. The 10W-30 will thicken the most.http://www.bobistheoilguy.com/motor-oil-108/


The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct



The extended drain interval is not adding another 5000mi to the recommended interval it's extending it to 5000mi.

How did those old diesels last for so long with that thick nasty oil that does not lubricate at start-up?
(sarcasim)
 
#17 ·
Well **** farmer john. You quote BITOG articles, and yet you utterly FAIL to comprehend them. They said exactly what I said.

Finally, just to shut your dumb *** up, I went on to Cummins Quickserve and got the operators manual for the 6.7. Under section 31-018-003 Lubricating Oils Recommendations and Specifications is a chart for recommended oil viscosity. I will post it here for everyone to appreciate:



Furthermore, the 6.7 manual refers you to Cummins bulletin 3810340. If you look at the chart in their bulletin, it adds 0w-40 to the "All season" list:



Again, for the cheap seats, YOU'RE WRONG!!!

Stings like a *****, doesn't it? :hehe:
 
#18 ·
Wow! Really an argument over which oil viscosity to use? Cummins / Dodge owners manual is pretty clear. I use 15w40 year long and Utah gets COLD in the winter and pretty warm in the summer and many oil analysis have indicated that my oil/engine are fine!
 
#19 ·
While so hostile MaxPF? We're all here to learn from one another.
 
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#20 ·
:popcorn:

im not trying to pick sides here im just a common folk that just uses what the manual suggested. but from what i understand(once again just a common folk) that chart shows 5w-40 and 15w-40 in the same temperature range. looks to me like you would have to go to a 10 or 5w-30 for the negative temp ranges. once again just going off the chart :thumbsup:
 
#21 ·
Here in Alberta I use 15w40 either dino or semi-synthetic. Once the temp hits -15C I plug it in. It will start in colder temp without being plugged in with the 15w40 but I feel it's too hard on the engine and it rattles pretty good. Never had an issue starting even to -40C as long as it is plugged in. With non diesels I always go to lighter oil in the winter. My Jeep uses synthetic 0W40 and occasionally I put in 5W40 synthetic. Not easy finding the 0W40. It would be pretty $$$$ to fill up the cummins with the 0w40 synthetic.
 
#25 ·
Holy cow, what's this world coming to? Name calling, disrespecting over what type of oil is good. For what it's worth I use olive oil, extra virgin seems to be the best, the downside is that it costs more than Amsoil. In all seriousness Obama is the moron, not a fellow cummins member.
 
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#26 ·
Thank you....that's what I was trying to say.
 
#29 ·
i still dont understand max. ur chart from cummins shows them at same temp. according to the chart u need to go with 30 for negative temps :confused:


Sent from my Autoguide iPhone app
 
#31 ·
i still dont understand max. ur chart from cummins shows them at same temp. according to the chart u need to go with 30 for negative temps :confused:
Correct. Which is an even bigger point for those people saying "Run 15w-40 no matter what!" MY point was that 5w-40 is approved by Cummins (as is 0w-40) - the naysayers were trying to say you MUST use 15w-40, and that 5w-40 is not approved by Cummins, which is clearly not the case.

Additionally, while Cummins approves 0w-40, 5w-40, and 15w-40 for the same temp range, 0 and 5w flows much better when the engine is cold, even if "cold" is 70 degrees. Thus, while all are approved, the oils with a lower cold weight rating (which are ALL synthetics BTW) will cause less startup wear.

that TSB states this...

For any Cummins engine models with light or normal service duty; Cummins allows an additional 5,000 mile drains when using Cummins Premium Blue & Valvoline Premium Blue Extreme

so this means a 5000 mile TOTAL between oil changes, correct?
No, it means an additional 5000 miles. If your interval is started as 5000 miles, Cummins will allow 10000 miles on their approved oils.

and as far as "living and breathing dodge" and "dodge doesnt care what cummins says". if dodge is going to cover my engine for 100k miles, your engine for 100k, and everyone elses for 100k.....i would think dodge/cummins has their bases covered as far as what oil to run. we're not reinventing the wheel here.
I find it difficult to believe that the Dodge owners manual states that ONLY 15w-40 is allowed under any circumstances. This directly contradicts Cummins' own recommendations and good practice. My guess is if you look carefully there is a chart identical to the one in the Cummins manual.
 
#33 ·
In other words, the Dodge manual shows that 5w-40 covers the same temp range on the high end as 15w-40, but goes well below zero on the low end. Which is exactly what I have been saying.

How about that caution requiring the use of 5w-40 below 0 degrees F. So much for the posters in this thread who seem to think it's fine to run 15w-40 regardless of temperature :doh: The silence from Snofarmer is deafening :hehe:
 
#37 ·
Valvoline Durablend Diesel Semi-Synthetic 5W40 Engine Oil (5 Litre)
HPR DIESEL 5 SEMI SYNTHETIC
5W-40 Diesel Motor Oil Semi-Synthetic (1 Liter) - Liqui Moly LM2021
5W40 API CI-4 HANATA Premium Diesel Engine Oil, Semi-Synthetic
Gulf Tec Plus 5w-40 semi-synthetic engine oil - diesel

I can keep on going...
 
#40 ·
even though there was a lot of bickering, if you pick through the posts you can get some facts out of it. one of them i found on my own on dodges web site lol. i kind of felt dumb when i went in and saw that "wow...why didnt i think of that before". i dont have any of that info in the books i got in my glove compartment.

the one think i am still a little leery about is that TSB that i looked up and posted......stating that you can literally DOUBLE your miles when using valvoline PB oil. i guess a guy could run 7-8000 miles on it and run a sample to see whats going on.... i know john deere claims you can run 50% more hours on their new engines if you run THEIR oil and filters. but double the oil life is a little questionable....for me anyways.

also, i ended up getting 15w40 this go round. i doubt ill have 5k miles on this oil by the time the winter comes, but maybe i will by the time it gets really cold. then i can throw some 5w40 in it.
 
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