Monograde 30WT/40WT in a PSD?

Joined
May 7, 2010
Messages
1,732
Location
Ocala, Florida
Hi guys, been contemplating something different with my next OCI in the 05 PSD. Many of you know how critical oil is in the 6.0 with the HEUI system. They shear a 40WT down to a 30WT in no time so ideally the less VII's the better right? Right now I have Valvoline Premium Blue 15W40 in her but it absolutely hates this oil! Rough starting and lopes for a few minutes as well as you can literally feel the "sluggishness" versus the 10W30 Rotella/Delo I usually run. Anyway, I'm in central florida, its getting very warm so no cold starts for me! We work the truck all summer with towing horses and hauling hay so I'm thinking about running a good HDEO monograde! What do you guys think? Good idea or bad? should I go with a 30WT or 40WT?? I figure without any VII's it should be very stable and not shear near as bad, right?
 
Joined
Apr 4, 2016
Messages
2,030
Location
Oregon
If you feel like you're having "sluggishness" with a 15W. A mono 30 or 40 can only be worse. I'd run a 5W-40 synthetic. Easier starts, and if it shears to a 30 it's not really an issue.
 
Joined
Sep 30, 2013
Messages
14,651
Location
Indiana
A 6.0 is sluggish by nature. With your climate, a mono grade would be fine with no negative impact. 15w40 is fine though.
 
Joined
Oct 9, 2004
Messages
12,451
Location
Cincinnati, OH, USA
Amsoil makes a straight 30 synthetic with no VIIs-ACD SAE 30, still meets 10W30 cold flow specs. Personally I would just put a Big 3 10W30 HDEO in it & forget about it for 7500 miles.
 
Joined
Nov 8, 2017
Messages
621
Location
California
Amsoil SAE 30 (ACD) cold weather performance exceeds a 10w30 with no VII. I don’t believe their AME 15w40 uses any VII either. Both are CI-4+ rated. Either one or a blend of the two would be ideal depending on what HTHS you’re looking for. There about $30 a gallon if you get the PC membership. I don’t think there is any better oil out there in that older specification.
 
Joined
Jul 4, 2016
Messages
2,008
Location
Jacksonville, FL
Originally Posted By: racin4ds
Hi guys, been contemplating something different with my next OCI in the 05 PSD. Many of you know how critical oil is in the 6.0 with the HEUI system. They shear a 40WT down to a 30WT in no time so ideally the less VII's the better right? Right now I have Valvoline Premium Blue 15W40 in her but it absolutely hates this oil! Rough starting and lopes for a few minutes as well as you can literally feel the "sluggishness" versus the 10W30 Rotella/Delo I usually run. Anyway, I'm in central florida, its getting very warm so no cold starts for me! We work the truck all summer with towing horses and hauling hay so I'm thinking about running a good HDEO monograde! What do you guys think? Good idea or bad? should I go with a 30WT or 40WT?? I figure without any VII's it should be very stable and not shear near as bad, right?
Tractor supply has all fleet SAE 30 and SAE 40 in 2.5 and 5 gallon pails. Should be a shoe in for your application so long as it has a compression ignition rating CF/CI/CJ. I'd run it!
 
Joined
Dec 12, 2006
Messages
130
Location
Texas
Some oils shear more than others. It takes 5k + miles to shear Mobil Delvac 1 to the TOP of the 30 wt range. Same thing w/ Schaeffer 5W40. Mobil 1 TDT isn't quite as shear resistant, but close. All of these are still in the high end of the 30 wt range at 7.5k miles. Valvoline PBE sheared more quickly than any oil I ran, and I saw my iron numbers start to increase with it. They came back down w/ the Mobil oils. One data point doesn't mean much statistically on the iron, but I have quite a bit of viscosity data. My 6.0L is far from sluggish - winter or summer. Unless it had the cold pour ratings of 10W30 as mentioned above, I think it would be a poor idea.
 
Last edited:
Joined
Oct 17, 2004
Messages
3,394
Location
Midwest, Illinois
VPB 10w30 worked very well for me. I'm surprised you have any lope or nail when cold in Florida. FICM voltage good? Mobil 1630 is a great monograde oil. Specs very similar to Delo 15w30, at half the price. Shell 30 is at WalMart, at least in the Midwest. Delo 30 is at Amazon. All would be fine in Florida
 
Joined
Oct 4, 2012
Messages
1,337
Location
Rabbit Creek, Alaska
If it’s sluggish in central Florida in almost June, you could put 0w20 in it and it would do the same. Above freezing shouldn’t even stress it on virtually any cheap 15w40. Look at stiction eliminator from hot shots secret (or have your injectors repaired/replaced) and keep using a full synthetic 40wt multigrade.
 

racin4ds

Thread starter
Joined
May 7, 2010
Messages
1,732
Location
Ocala, Florida
Originally Posted By: dlundblad
A 6.0 is sluggish by nature. With your climate, a mono grade would be fine with no negative impact. 15w40 is fine though.
My 6.0 was not sluggish whatsoever on 10W30! It started easier, sounded better even in the freezing cold mornings while we still lived in VA.
 
Joined
Jan 1, 2015
Messages
154
Location
Charles City, Iowa
I live in northern Iowa. I am 61 and we ran straight 30 and straight 40 in everything on the farm for years even thru our winters and never lost an engine. Now we run 15w-40 HDEO in everything from my Harley to my wife's Edge with 230,000 miles on it. Every tractor and truck engine runs it here. My 06 6.0 runs it also and I have never touched that motor yet and it lives on our horse trailer. I would not have one bad thought about running straight 30 or 40 in it. If your 6.0 is sluggish I would have the Atlas 40 tune installed in your FICM. I added the Atlas 80 to mine and what a difference. Your sluggishness is not from the oil. It is from tuning that ford had to put in for the EPA. By changing to the Atlas tune it puts the fuel back into the lower rpm's. The EPA made them tune them this way for smoke control.
 
Last edited:
Joined
Sep 6, 2015
Messages
6,195
Location
Kalifornia Kollective
Any xW-30 is supposed to be 30 at op temp. There will be no additional resistance at temp. A straight grade might be a little different on start-up, but I doubt you'd be able to tell much of a difference. Can't shear - no VII's. Plenty good straight grades out there. Drop by local tractor shop. They should have some in stock. If not, there is always Amazon: Delo 30 smile We need someone to help dispel the myths that straight grades are "weird"... They are the preferred for many commercial applications. Try it and tell us what happens. It will not hurt the engine. My guess is that it will run fine and stay in grade for a full cycle ... Should act just like a fresh xW-30 right after a change w/o the downside as it gets further into the OCI cycle ... I don't have a PSD, or I'd have tried this a long time ago laugh
 
Last edited:
Joined
Dec 12, 2006
Messages
130
Location
Texas
With the 6.0L PSD, the issue w/ the straight grade would be more of an injector issue than a lubrication issue. Spool valve stiction mainly.
 

racin4ds

Thread starter
Joined
May 7, 2010
Messages
1,732
Location
Ocala, Florida
Originally Posted By: bismic1
With the 6.0L PSD, the issue w/ the straight grade would be more of an injector issue than a lubrication issue. Spool valve stiction mainly.
The grade of oil has nothing to do with stiction in the 6.0... its caused by varnish and lack of maintenance as well as poor tolerances. Remember, with a 10Wxx or 15Wxx oil it is running either a 30 or 40WT all the time when warm anyway.
 
Joined
Dec 12, 2006
Messages
130
Location
Texas
On a cold engine, a heavier grade of oil will show the stiction issues. That is why more 6.0's have stiction problems on a cold startup with 15W40 than 5w40. The issue is typically not what grade it is hot ............ As we ALL know, a hot 40wt viscosity is much lower than a cold 5Wt ......... Check out all the "hard starts when cold" and "rough running when cold" posts on the 6.0L forums. If only the 6.0L injectors would have had the spring assisted return of the poppet that the 7.3L injectors did. The injectors (upgraded) with the "relief cut" seem to have significantly reduced the stiction issues regarddless of the cold weight - still lots of original injectors still out there.
 
Last edited:
Top