Rotella 5w40 vs 10w-30

[dnewton3]

Relative to the temps, I was speaking to the OP who is in NJ, running a gasser truck. There is no concern for cold in that area.

As for the fuel econonmy, each sub-topic is relative. A 5w-40 and a 15w-40 are both a 40 grade at full temp. He's not not going to see any singificant (if discernable) fuel mileage increase going to a syn 5w-40 verus a dino 15w-40.

Going to a thinner fluid (30 grade) will help somewhat.

He has a low annual mileage; 3k miles a year and then he OCIs. He's in NJ; not know for bitter cold. He has a gasser; no concern for compression ignition in cold areas. He's going to use it pushing snow; how much concern can he really have for fuel economy? When you're pushing a load like that, it's VASTLY different than running at light-throttle down the highway at a moderat speed. He'd dreaming if he thinks he'll affect his fuel economy by differentiating between a 5w-40 and a 15w-40 in his application.


Q: Why in the world would he "need" a synthetic or even a semi-synthetic?
A: He doesn't. He just wants one.


What would serve him well is any decent 5w-30 PCMO. Good start up, good economy, good protection.

 

[bullwinkle]

If I was towing heavy, plowing, and trying to clean up an (at least partially) sludged-up motor-I would probably run a dino HDEO-such as a 10W30 Rotella, Delo, Delvac 1300, whatever you can find. If not the 10W30, then 15W40. I would (think) with the heavy loads that the 5W30 would burn off, and the HDEO would also help with the sludge. But I haven't run too many gas engines as hard as the OP and Dave have, either-other than the 350 Chevy/Mercruiser boat motor (which loves the Delvac 1300 15W40, a dual-rated HDEO).

 

[04SE]

Just put Rotella T5 10w30 in it. Dino and synthetic and HDEO. Everyone wins.

 

[rufushusky]

Originally Posted By: 04SE
Just put Rotella T5 10w30 in it. Dino and synthetic and HDEO. Everyone wins.


^^ agree, great oil and $16 bucks a gallon at wally world.

 

[italian68]

thanks guys, t5 10w-30 it is!

 

[dnewton3]

T5 for 3k miles a year in a gasser; what a waste of money and oil. You could get 10w-30 dino HDEO for less money, but I suspect you simply cannot allow yourself to "stoop" to a conventional oil, so be it.


T5 is probably a good choice for you. Not because it's a wise decision, but because it makes you happy. That is the overall deciding factor. To be honest, it's not needed, but it will probably satisfy your emotional need, even though there is no mechanical need.

I wish you well. Happy plowing.

 

[rufushusky]

Originally Posted By: dnewton3
T5 for 3k miles a year in a gasser; what a waste of money and oil. You could get 10w-30 dino HDEO for less money, but I suspect you simply cannot allow yourself to "stoop" to a conventional oil, so be it.




Well one thing to remember 10w-30 HDEO is a little hard to come by in some parts of the country. I am about 25 miles south of Boston, MA and MC 10w-30 is 5 bucks a quart and Rotella 10w-30 has to be ordered and is 18 bucks a gallon so t5 at 16 a gallon at wally world is the cheapest 10w-30 HDEO that I can find easily. There a is a JD place about 20 miles away that might have 10w-30 cheaper but it is only open M-F 8-5 so they won't work during tax season.

 

[dnewton3]

Another option to consider is that one might be able to extend the OCI out over two or three years.

If you have to spend a bit more money on the OCI, at least work to get the value from the fluid. It's not like warranty is a constraining factor. Three years in the crankcase might be easily doable.

 

[ltslimjim]

Originally Posted By: rufushusky
Originally Posted By: dnewton3
T5 for 3k miles a year in a gasser; what a waste of money and oil. You could get 10w-30 dino HDEO for less money, but I suspect you simply cannot allow yourself to "stoop" to a conventional oil, so be it.




Well one thing to remember 10w-30 HDEO is a little hard to come by in some parts of the country. I am about 25 miles south of Boston, MA and MC 10w-30 is 5 bucks a quart and Rotella 10w-30 has to be ordered and is 18 bucks a gallon so t5 at 16 a gallon at wally world is the cheapest 10w-30 HDEO that I can find easily. There a is a JD place about 20 miles away that might have 10w-30 cheaper but it is only open M-F 8-5 so they won't work during tax season.


I really don't understand how one could complain about $18 on oil once a year as being a waste of money and oil.

 

[italian68]

I really don't understand how one could complain about $18 on oil once a year as being a waste of money and oil.

+1

to put this in comparison, it takes over $100 to fill the tank. how many times a year will i do that...

 

[fpracha]

Originally Posted By: rufushusky
15w40 has viscosities of 118/15.2 @ 40/100*C
5w40 is 88.6/14.5 @ the same temps

So the 5w40 is significantly lighter/less viscous at 40*C but only slightly less viscous at operating temp...certainly not enough to make a difference in fuel economy IMHO.
up at Medford and daily short commutes from nov to march. Are you suggesting to use a 15w-40 even in the cold temperatures compared to the 5w-40 or is this just suggested for the OP here ?
Will changing from 5w-40 to a 10w-30 make any difference to the fuel economy?

 

[fpracha]

Originally Posted By: dnewton3
Another option to consider is that one might be able to extend the OCI out over two or three years.
Three years in the crankcase might be easily doable.
+1

 

[dnewton3]

Viscosity is the resistance to flow. More resistance takes more power to overcome. Therefore, a lighter grade oil will be easier to pump, and require less fuel to overcome, all else being equal. Any time you move from a heavier to a lighter grade, you'll see some gains in efficiency. But often they are very small are hard to distinguish in the real world.



As for temps, people so very often want to over-compensate for what they percieve as "cold". In this situation, for the OP, there is no "need" for a synthetic, as it just doesn't get that cold enough to warrant a "need" for the super-cold abilities of a full syn.

 

[fpracha]

Originally Posted By: dnewton3
As for temps, people so very often want to over-compensate for what they percieve as "cold". In this situation, for the OP, there is no "need" for a synthetic, as it just doesn't get that cold enough to warrant a "need" for the super-cold abilities of a full syn.
So at what temps do you suggest to start using a full syn?

 

[rufushusky]

Originally Posted By: fpracha
Originally Posted By: rufushusky
15w40 has viscosities of 118/15.2 @ 40/100*C
5w40 is 88.6/14.5 @ the same temps

So the 5w40 is significantly lighter/less viscous at 40*C but only slightly less viscous at operating temp...certainly not enough to make a difference in fuel economy IMHO.
up at Medford and daily short commutes from nov to march. Are you suggesting to use a 15w-40 even in the cold temperatures compared to the 5w-40 or is this just suggested for the OP here ?
Will changing from 5w-40 to a 10w-30 make any difference to the fuel economy?


Depends on the application, IMHO unless you have a HEUI (7.3 or 6.0 PSD or an older Cat engine) I would run a 15w-40 in SE Mass year round. Just doesn't get cold enough here IMHO. Really you could get by on a 15w-40 no problem in a HEUI too...it will just be like driving an oversized K-car when its cold.

Maybe a tiny fraction of an mpg but don't expect anything big. I went from a 15w-40 dino to a 10w-30 syn blend and didn't notice anything. My best tank ever (20.3 mpg) was actually with Delo 15w-40 in the engine...I am sure the better mpg had more to do with the 676 highway miles I drove that week though.

 

[dnewton3]

Originally Posted By: fpracha
Originally Posted By: dnewton3
As for temps, people so very often want to over-compensate for what they percieve as "cold". In this situation, for the OP, there is no "need" for a synthetic, as it just doesn't get that cold enough to warrant a "need" for the super-cold abilities of a full syn.
So at what temps do you suggest to start using a full syn?


Like everything else, it depends upon the situation, equipment, etc.

For my Dmax, GM recommends 15w-40 all the way down to zero F.

I'm not sure what the Ford/Navistar spec is for the 7.3L, but I suspect it's down around +20F or below that.

Keep in mind that an occasional "dip" below some theorhetical, arbitrary number on the thermometer is not going to signal imminent and immediate disaster for your equipment. Often, the wear isn't of the greatest concerns to a diesel in cold temps, but the compression-ignition starting. You need good rpm to get good heat into the cycle.

Given the OP is using a 5.9L gasser, cold starts in NJ are NOT an issue.

For anyone with a diesel, I'd say down to around zero a 15w-40 is OK. Below that, I'd consider at 10w-30 dino. I don't believe a synthetic will show a significant advantage until you get to around -20F. At that point, a diesel is going to need every bit of help it can get. But that does not describ SE Mass, either. The HEUI in the PSDs can benefit from thinner oil to operate the injectors. It helps reduce or eliminate the "romp" associated with cold starts in those engines.

It's all situationally dependent.

 

[rufushusky]

Originally Posted By: dnewton3

Like everything else, it depends upon the situation, equipment, etc.

For my Dmax, GM recommends 15w-40 all the way down to zero F.

I'm not sure what the Ford/Navistar rec'n is for the 7.3L, but i suspect it's down around +20F or below that.

For anyone with a diesel, I'd say down to around zero a 15w-40 is OK. Below that, I'd consider at 10w-30 dino. I don't believe a synthetid will show a significant advantage until you get to around -20F. At that poing, a diesel is going to need every bit of help it can get. But that does not describ SE Mass, either.


Per my owners manual 15w-40 is the preferred oil in a 7.3 above 30*F and can be run down to 10*F. A 10w-30 is acceptable from -20 to 90*F and is preferred below 30*F. Granted these reflect CG rated motor oil, which is VERY out dated. I know there are plenty of people running 15w-40 in a HEUI closer to zero. And THANK GOD that -20*F doesn't describe SE Mass. I already want to move as is!

 

[dnewton3]

Thanks for sharing the info; it's been a while since I've seen that.

Clearly I was a bit off, but not by much!

 

[rufushusky]

Originally Posted By: dnewton3
Thanks for sharing the info; it's been a while since I've seen that.

Clearly I was a bit off, but not by much!



Actually I was off too, 10w-30 is good til -10*F, not -20*F. Regardless...way too cold.