10w-30 vs 5w-40 question

Status
Not open for further replies.
Joined
Sep 2, 2015
Messages
1,291
Location
Texas
Hello all,

I am pretty convinced in going with 10w-30 once my stock (2 more oil changes) of 5w-40 synthetic runs out on my 2014 Ford F550 powerstroke 6.7. However, since it is a motorhome, it can sit anywhere from 15-20 days at a time without being run (am pretty good at keeping it in good working order).

My only question or concern is...does 10w-30 stay/remain on the metal surfaces the same as 5w-40 (heavier weight oil)? Would a 40 weight vs. a 30 weight oil provide better protection (maintain oil stays on the metal surfaces) better between longer start intervals?

Just curious if that is even a factor or consideration I am overlooking?
Thanks to all again in advance.
 
use the manufacturer recommended weight.

Only trial and error will tell you if 10w30 would work but I doubt it's worth the try. Have you read forums where a significant amount of people have tried this without any ill effects? if not, I don't see why risk anything.

0w40,5w40,10w40, and maybe even 15w40 would be okay, especially if you don't see below freezing temperature.
 
Yes, Ford recommends 5w40 for severe service, 10w30 for normal conditions and 15w40. Just curious if there is a difference in protection for trucks that don't run everyday.
 
Lots of Euro 5W-40 Pennzoil at AutoZone for $2, pickins is getting slim though...

However, the Pennzoil non Euro 0W-40 seems to be unwanted. May make a good substitute...
 
Originally Posted By: 01_celica_gt
use the manufacturer recommended weight.


I looked it up:

2014 FORD TRUCKS F550 PICKUP 6.7L 8-cyl Engine Code [T] Turbo Diesel

LUBRICANTS & FLUIDS:

Engine Oil
Grade 1......CJ-4

Above 0 F........10W-30 [1]
Above -20 F......5W-40 [2]
Above 19 F......15W-40 [3]
Below 50 F........0W-30, 0W-40

[1] Recommended for normal usage only.
[2] For severe duty service, use 5W-40
[3] For the use of biodiesel grade B20 max
use SAE 5W-40 or SAE 15W-40
 
SAE grade is really irrelevant to how long the surface film remains. Any viscosity-related film effects will be done by 24-48 hours into the weeks of storage. The rest of it is purely molecular adhesion and is extremely complex. Some people say that high percentages of ester-based lubricants help. All I can say is I've opened junkyard engines that had been there for years if not decades, and the only time I've found "dry" internal surfaces without a pretty hefty oil film was when the engine had already been opened to the elements. If all the caps are in place (even if the hood's been removed), I hust haven't seen this as an issue.
 
Originally Posted By: Merkava_4
Originally Posted By: 01_celica_gt
use the manufacturer recommended weight.
I looked it up:

2014 FORD TRUCKS F550 PICKUP 6.7L 8-cyl Engine Code [T] Turbo Diesel

LUBRICANTS & FLUIDS:

Engine Oil
Grade 1......CJ-4

Above 0 F........10W-30 [1]
Above -20 F......5W-40 [2]
Above 19 F......15W-40 [3]
Below 50 F........0W-30, 0W-40

[1] Recommended for normal usage only.
[2] For severe duty service, use 5W-40
[3] For the use of biodiesel grade B20 max
use SAE 5W-40 or SAE 15W-40

This is correct for all of the 6.7L applications; and I have waffled on this on my own PSD. TBH, it **seems** like 10W-30 is a token offering because to get into severe duty takes very little to cross that line--extended idling, using biodiesel, towing, usage in high or low temperatures, etc.). I plan to use 5W-40 most of the time and 15W-40 the remainder of the time (perhaps a 70/30 mix of 15W-40 and 5W-40 in the summer).

OP - I would not worry about "oil clinging" between the two viscosities--it is a moot point and of no consequence.
 
Can't speak to the Stroke, but my Detroit Series 60 12.7L does great on a 10w30. I didn't tear the motor open to check, but I noticed no difference in start crank time after the truck had recently sat for 3 weeks in approx 35F temps. And the oil does a great job pulling around 80K lb of truck and load. Detroit offer up recommendation for 15w40, 10w30, 5w40 for the Series 60, with 10w30 approved for year round use. Fact is, every major heavy diesel OEM is factory filling with 10w30 now and has been for a while. I am quite sure they have done similar testing as the OP is asking for and not found it to be an issue.
 
Thanks again for all the info. Definitely interested in trying 10w30 as UOAS have alleviated my concerns about engine wear issues. Just was curious the state of oil on the metal after not running for 2-3 weeks...I remember Ford recommends running/driving every 15 days to maximize component longevity....so was curious about vehicles not driven every day.
 
Note that at least one of the big synthetic 5w-40 grades has a bit of ester in it, too, for what it's worth. At least that was indicated in the discussions here contemporary to its roll out.
 
You will have no issues with 10w-30 in your application, and I have engines that sit for six months or more without being run. Its just part of life as they're not human and don't remember as some of these engines I have are approaching 70 years old and start fine and are put to work.
 
Oh ok. Thanks. Was wondering about letting it sit too long before running it. Garak, what do you mean about one 5w40 has bit of ester in it? Thanks to all again.
 
%w-40 will cover your operation from -20 to +100*f. $4.00 more per gallon and change the oil annually. done .
 
Originally Posted By: mbacfp
Garak, what do you mean about one 5w40 has bit of ester in it?

When Delvac 1 ESP 5w-40 was being released, there was talk of a splash of ester being in the formulation, for whatever it's worth.
 
Originally Posted By: mattwithcats
Lots of Euro 5W-40 Pennzoil at AutoZone for $2, pickins is getting slim though...

However, the Pennzoil non Euro 0W-40 seems to be unwanted. May make a good substitute...


Both of those Pennzoil grades are "unwanted" for $2 at my local AZ. By next week some of those might get to $1.
 
Originally Posted By: Garak
Originally Posted By: mbacfp
Garak, what do you mean about one 5w40 has bit of ester in it?

When Delvac 1 ESP 5w-40 was being released, there was talk of a splash of ester being in the formulation, for whatever it's worth.


The flashpoint of D1 ESP 5w40 is one big difference compare to TDT or other CJ-4 5w40. Now...is that base oil or additives that are impacting that?
 
Status
Not open for further replies.
Back
Top