I just did change #3 in mt F250. Im at 14,000 miles and went from Rotella T6 (5-40) to Delvac 15-40. The Delvac is obviously much thicker than the Rotella. What I am wondering is if the 15-40 is OK to run this winter. Im in NC and it doesnt get crazy cold here. Now that I have my drain valve installed I am planning to run dino oil and just change at factory OCIs. I have used Wix filters for the last 2 changes but will probably go back to motorcraft in the future. Any thoughts form the forum?
Delvac 15-40 in NC
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For N Carolina you'll be fine with 15W40, just let it idle for a minute if you have a cold snap below freezing.
I'd recommend using factory filters for many reasons - warranty (including damaged engine if the filter fails), proper internals like relief valve setting, correct O ring....
Which Delvac 15W40 are you using? Which engine/what year?
As far as the "thicker" observation, 15W40s are definitely thicker than 5W40s at room temp but at 100C the difference is usually less (14.2 for T6 vs 15.x for typical 15W40) and at 150C (HTHS) even less difference.
Charlie
I'd recommend using factory filters for many reasons - warranty (including damaged engine if the filter fails), proper internals like relief valve setting, correct O ring....
Which Delvac 15W40 are you using? Which engine/what year?
As far as the "thicker" observation, 15W40s are definitely thicker than 5W40s at room temp but at 100C the difference is usually less (14.2 for T6 vs 15.x for typical 15W40) and at 150C (HTHS) even less difference.
Charlie
I have the 6.7 powerstroke and I believe it's the Delvac 1300 super in 15-40. It was on sale at Wal-Mart for $12.97 a gallon.
If it goes below 20 degrees I will move... I will be back in Geogia within the next 18 months anyway.
Doesn't that engine spec a 10w-30?
I already know it does I'm curious as to why and many other powerstroke owners don't run it.
I already know it does I'm curious as to why and many other powerstroke owners don't run it.
dnewton3
Staff member
Originally Posted By: roadrunner1
Doesn't that engine spec a 10w-30?
I already know it does I'm curious as to why and many other powerstroke owners don't run it.
Answer: brand/grade/base stock bias ...
I cannot fathom NC getting cold enough to make any differnce at all in wear protection or starting, but some folks just think thicker is "better". The OP will be fine, but might lose out a bit on fuel economy.
The newer common rail engines with intake heaters are pretty easy to start anyway. While Charlie probably does have a legit need for the performance edge of syns and such, few of the rest of us have a true need for such extremes.
As you and I have proven, thinner HDEOs work every bit as well as thicker grades, even under heavy working conditions.
Doesn't that engine spec a 10w-30?
I already know it does I'm curious as to why and many other powerstroke owners don't run it.
Answer: brand/grade/base stock bias ...
I cannot fathom NC getting cold enough to make any differnce at all in wear protection or starting, but some folks just think thicker is "better". The OP will be fine, but might lose out a bit on fuel economy.
The newer common rail engines with intake heaters are pretty easy to start anyway. While Charlie probably does have a legit need for the performance edge of syns and such, few of the rest of us have a true need for such extremes.
As you and I have proven, thinner HDEOs work every bit as well as thicker grades, even under heavy working conditions.
Honestly I went with the Delvac because it was on sale. I am having a hard time finding conventional oil in any grade other than 15-40. Semi and full synthetics are available in other grades but the cost is nearly double.
I have noticed a decrease of about 1.5 mpg (on the computer) since changing the oil. I guess I need to do a little more shopping around. Thanks for all of the input.
I have noticed a decrease of about 1.5 mpg (on the computer) since changing the oil. I guess I need to do a little more shopping around. Thanks for all of the input.
A decrease of 1.5 mpg = 7-10% is quite significant if real.
Crunching the numbers it would probably pay to use either 10W30 or even the synthetic. If it is that viscosity sensitive in terms of fuel usage then Mobil's new Delvac 1 LE 5W30 (meets CJ4 but also ACEA E6 and MB 228.51) might give the very best fuel economy.
Charlie
Crunching the numbers it would probably pay to use either 10W30 or even the synthetic. If it is that viscosity sensitive in terms of fuel usage then Mobil's new Delvac 1 LE 5W30 (meets CJ4 but also ACEA E6 and MB 228.51) might give the very best fuel economy.
Charlie
I guess going the cheap route wasnt the best decision. At least the next change will be easy now that I have installed the drain valve. Looks like I have a very slight leak coming from the filter as well. I made sure the old o-ring came off with the old filter and it's definitley not cross threaded so not sure what is up with the leak. Same Wix filter I used last time, bought two at the same time. Looks like it will be motorcraft filters from now on. I am going to have to find a different source for my oil as Wal-Mart is limited in this area.
I have over 200 fill ups on my 2.2L 4 cyl. Honda and I have used 0/30, 5/30, 5/40 and 10/40 and have not seen any measurable difference in my gas mileage. If I lost 1.5 mpg because of the oil I used, it would be out after 2 or three tanks of gas.
All of the specs I have seen 15w-40 is good until 4f, in NC I surely wouldn't worry about draining early unless you want to get your leak fixed.
But for your next OC I would look into a 10w-30 as its the preferred viscosity for your truck.
But for your next OC I would look into a 10w-30 as its the preferred viscosity for your truck.
dnewton3
Staff member
I would caution against making a hasty decision on fuel economy after one oil change.
To really make a fair comment, you'd need to be able to switch back and forth, over multiple seasons, to normalize data and discount input variance.
I am confident that going to a thicker oil is going to degrade fuel efficiency, but to say by how much after one oil change is too soon to tell. Don't let a few tanks mislead you. You need to average them over a long time, accoutning for type of vehicle use, weather, driving conditions, etc. And then switch back and forth, and see if you can delineate the differential variable with input selection.
To really make a fair comment, you'd need to be able to switch back and forth, over multiple seasons, to normalize data and discount input variance.
I am confident that going to a thicker oil is going to degrade fuel efficiency, but to say by how much after one oil change is too soon to tell. Don't let a few tanks mislead you. You need to average them over a long time, accoutning for type of vehicle use, weather, driving conditions, etc. And then switch back and forth, and see if you can delineate the differential variable with input selection.
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