Diesel Motor Oil

July 26, 2018, 11:47 AM

FootbrakeJim

Diesel Motor Oil

Just hit 10,000 miles on the truck I bought used in March.
I had to change the oil almost immediately, since the dealer tech had reset the oil life monitor, but failed to actually change the oil & filter. At that time I used Shell Rotella, since it is a brand of Diesel oil that I have heard good things about for many years, (and it was on sale in the 2.5 Gallon jug, which is exactly what I needed for the 10 quart crankcase capacity of a Duramax). During one of the discussions on this forum, TD3550 shared some info on a preference that many big rig truckers have for Mobil Delvac. My next oil change was done 4,000 miles later, which is the interval I am using, (I believe the monitor must go about 7,500 as it shows around 45% remaining at 4K miles). I went with Delvac, and I am about ready to change it again. I can say that the Delvac does seem to maintain slightly higher viscosity at high temps than the Rotella, (both in 15W40, non-synthetic), and seems to be more stable/consistent, both of these observations are being made with regard to oil pressure.
The hot idle oil pressure shows a few PSI higher with Delvac than it did with Rotella, and what really surprised me, is that indicated pressure is exactly the same after a 1 hour drive at fast highway speeds, in the ambient temperatures of 108-110* that we had last week, as it was after a 20 minute drive in 75-80* weather. I do realize this does not necessarily mean it protects better against wear, etc.

What I really wanted to share, was the deal going on right now if you have a diesel, and need to do an oil change any time soon. My local O'Reilly auto parts has Delvac 15W40 on sale for $13.99 per gallon, AND Mobil is also offering a $7 per gallon Rebate on it through the end of the year. So your final price per gallon ends up being only $6.99! (That is for a Gallon, less than many oils cost for a Quart!)

Nothing to mail, either. You can submit your rebate request online, using your phone, just snap a picture of the receipt and upload it directly. You can submit a max of 2 rebate requests, with a max total of up to 10 quarts. SO that is a savings of $70, on top of the savings from the discounted sale price. And you'll see at the link they offer even larger rebates on their other diesel oils, and for 5 Gal buckets, or 2.5G jugs, (wish I could find those).
Not trying to sell anyone's product, and I do not work for any oil company or parts store.

Just trying to help some folks save some money for race day.

Here is the rebate website: Delvac Rebate Link

This message has been edited. Last edited by: FootbrakeJim,

July 26, 2018, 01:53 PM

fastman-99

Your throwing money away changing the oil at 4000 miles.

July 26, 2018, 02:42 PM

FootbrakeJim

quote:
Originally posted by fastman-99:
Your throwing money away changing the oil at 4000 miles.

Fastman, I am open to suggestions on oil change intervals, particularly if they come from anyone who has put 300,000 mile or more on a turbo diesel pickup with all the new emissions junk like SCR, DPF, and especially EGR.
I know one thing, GM, Ford, & Dodge do not necessarily want you to drive one for that many miles, instead of letting them sell you another one. So there is no way I am going 7,000 miles or more between changes. Heck, these things dirty 10 quarts of fresh oil to midnight black in less than 1,000 miles. I have always been a bit a n a l about changing my oil, (Usually around 3K miles on gas), but my 4 most recent gas powered Chevy's have had over 280,000 miles on them when I sold them, and none ever smoked at all, or required any major repairs. And all of them had the same exact power as the day I bought them. So I intend to drive this one at least that long, and sure don't want to have to pull or do any internal repairs to the engine.

July 26, 2018, 03:44 PM

Slick Vic

Amsoil, put a bypass filter system on it. Get oil tested every 5-6000 miles. I went 18,0000 miles last time, they said i was ok but changed it and the filters just for good measure.

July 26, 2018, 04:33 PM

"The Bender"

My Ram/Cummins has 9300 heavy towing (28K combined) miles on the oil and the monitor still shows 38% oil life left...…..

July 26, 2018, 04:57 PM

TD3550

Contributing factors on Clean oil to black oil
(Soot)
Incomplete combustion
EGR efficiency
Ring gap.(Larger)(Diesel)
Low percentage of fuel get past the rings and into the oil.
Oil, fuel dilution
Average Compression ratio's (diesel) 22.1
Oil analysis always a plus.

Just to mention a few. I have never changed my
feelings on intervals for 45 plus years. I take extended life oil changes with a grain of salt.

One company i serviced for years decided to go from a 25K interval too 100K interval.Reason being.. The bottom line. cost.But like some they get bit in the end.

July 26, 2018, 05:15 PM

Tony Barrett

We did a lot of testing for my company's fleet. We use Amsoil and found the most common reasons for failure were fuel dilution and contamination most commonly coolant. I use Amsoil and their 25,000 mile filter in my personal dually. I changed it once a year and never had a problem.

July 26, 2018, 05:25 PM

Eman

I use Mobil oils in everything I own and have for many years. I poured a lot of Mobil oil when i had my shop. That said my diesel customers all wanted Rotella so that's what they got. I can't say that there is any difference in how a vehicle will last with either. The one vehicle I have a lot of experience with is a fiend's 94 GMC with a 6.5 Turbo diesel. Oil changed by me from the first oil change as I worked at the dealer where it was purchased new. Rotella every oil change with intervals about 5k mi. It now has 325,000 mi. and never had a valve cover off. Only engine repair was 1 injector about 15 years ago.
That's a real deal on Delvac and I'll have to buy some. only diesel I service of mine is a farm tractor.

July 26, 2018, 11:39 PM

J178RED

Eman glad to see your post, my 2007 Dodge 5.9 3500 has a treatment done at 5k with Rotella since new. It is just gotten to the breakin point of 200,000 and its a great running and great mileage beast....Broke at high pressure line once but that's it. Tires, oil, filters cheap stuff.....OPPS and a A/C compressor 50,000 miles ago...LOL

July 27, 2018, 04:51 AM

fastman-99

quote:
Originally posted by FootbrakeJim:
quote:
Originally posted by fastman-99:
Your throwing money away changing the oil at 4000 miles.

Fastman, I am open to suggestions on oil change intervals, particularly if they come from anyone who has put 300,000 mile or more on a turbo diesel pickup with all the new emissions junk like SCR, DPF, and especially EGR.
I know one thing, GM, Ford, & Dodge do not necessarily want you to drive one for that many miles, instead of letting them sell you another one. So there is no way I am going 7,000 miles or more between changes. Heck, these things dirty 10 quarts of fresh oil to midnight black in less than 1,000 miles. I have always been a bit a n a l about changing my oil, (Usually around 3K miles on gas), but my 4 most recent gas powered Chevy's have had over 280,000 miles on them when I sold them, and none ever smoked at all, or required any major repairs. And all of them had the same exact power as the day I bought them. So I intend to drive this one at least that long, and sure don't want to have to pull or do any internal repairs to the engine.

Between me and my dad and brother we are on are 6th emissions type diesel. and 5th 6.7 ford. We dont keep them to 300k miles but we put still use them for what there for. We change oil at 10k miles with no issues. And I would be willing to bet we could go longer if we got the oil tested. Run a good synthetic oil of your choice, I prefer rotella and change it at 7500-10k with no worries. Gas vehicles today, with the oil technology available are going 7-10k miles on oil changes. Diesels can go further than that. Took me years to get my dad to realize that 3k miles on his highway car was a waste, but he is on board now.

July 27, 2018, 05:05 AM

racerdude2054

rotella for me every 10K miles

July 28, 2018, 02:38 PM

Alaskaracer

Amsoil oil and filter here, change it when the oil life monitor tells me to. Average oil change is approximately 12,000 miles. I've ran other oils before and can honestly say one thing about Amsoil. I get better average fuel economy when I run Amsoil than any other oil. It's not much, but enough to notice. I track mileage and fuel economy religiously with my truck and the numbers don't lie. Even with my driving.

July 28, 2018, 07:34 PM

Mike Beck

The nearest O'Reilly store to us in only a scant 93.5 miles away........ Guess we will look at our local chains here and see what it sells for.

July 29, 2018, 07:58 AM

Bucky

quote:
Originally posted by Coloradoracer:
Amsoil oil and filter here, change it when the oil life monitor tells me to. Average oil change is approximately 12,000 miles. I've ran other oils before and can honestly say one thing about Amsoil. I get better average fuel economy when I run Amsoil than any other oil. It's not much, but enough to notice. I track mileage and fuel economy religiously with my truck and the numbers don't lie. Even with my driving.

What do you attribute the better mileage to? Is it lower viscosity? Honestly, over the years I have become very sceptical about claims about the abilities of motor oils to improve engine performance or lengthen engine life.

July 29, 2018, 01:56 PM

Alaskaracer

Bucky, I wish I had an answer. All I do know is that I get my best economy when I run Amsoil vs anything else. I'm not going off any claims, just what I've noticed. Typically in city driving I'll see about .25-.5 mpg average over a tankful of fuel. Highway I've gotten as much as 1.5 mpg, but usually in the .5-.75ish range. Like I said before, not a lot but enough to notice. I can change the oil with something else and the change in economy is pretty much instant. The worst was rotella. Not saying you or anyone else will get the same result, that's just what I had. I do track my fuel economy closely in my truck. I've also noticed different economy depending on where I purchased my fuel. I tried to purchase my fuel from one location as often as possible as well when I found a source that my truck seemed to prefer.

July 29, 2018, 10:34 PM

rusty

whats wrong with useing oil change light or indicator in dash

July 31, 2018, 09:42 AM

BP758

quote:
Originally posted by FootbrakeJim:
Just hit 10,000 miles on the truck I bought used in March.
I had to change the oil almost immediately, since the dealer tech had reset the oil life monitor, but failed to actually change the oil & filter. At that time I used Shell Rotella, since it is a brand of Diesel oil that I have heard good things about for many years, (and it was on sale in the 2.5 Gallon jug, which is exactly what I needed for the 10 quart crankcase capacity of a Duramax). During one of the discussions on this forum, TD3550 shared some info on a preference that many big rig truckers have for Mobil Delvac. My next oil change was done 4,000 miles later, which is the interval I am using, (I believe the monitor must go about 7,500 as it shows around 45% remaining at 4K miles). I went with Delvac, and I am about ready to change it again. I can say that the Delvac does seem to maintain slightly higher viscosity at high temps than the Rotella, (both in 15W40, non-synthetic), and seems to be more stable/consistent, both of these observations are being made with regard to oil pressure.
The hot idle oil pressure shows a few PSI higher with Delvac than it did with Rotella, and what really surprised me, is that indicated pressure is exactly the same after a 1 hour drive at fast highway speeds, in the ambient temperatures of 108-110* that we had last week, as it was after a 20 minute drive in 75-80* weather. I do realize this does not necessarily mean it protects better against wear, etc.

What I really wanted to share, was the deal going on right now if you have a diesel, and need to do an oil change any time soon. My local O'Reilly auto parts has Delvac 15W40 on sale for $13.99 per gallon, AND Mobil is also offering a $7 per gallon Rebate on it through the end of the year. So your final price per gallon ends up being only $6.99! (That is for a Gallon, less than many oils cost for a Quart!)
Nothing to mail, either. You can submit your rebate request online, using your phone, just snap a picture of the receipt and upload it directly. You can submit a max of 2 rebate requests, with a max total of up to 10 quarts. SO that is a savings of $70, on top of the savings from the discounted sale price. And you'll see at the link they offer even larger rebates on their other diesel oils, and for 5 Gal buckets, or 2.5G jugs, (wish I could find those).
Not trying to sell anyone's product, and I do not work for any oil company or parts store. Just trying to help some folks save some money for race day.
Here is the rebate website: Delvac Rebate Link

Good info thanks. Delvac, Rottella and Delo all great oils. Change the trans fluid to Delvac also. Allison approved TS295 and better.