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i need your opinion as to which oil is a better oil i had been running chevron supreme 10w 40 but i switched to shell rotella 15w 40 which oil do you think is better this is for my 03 expy 5.4
I think Rotella and the Chevron Delo are pretty close (I use Rotella), but here's some objective info from an earlier thread on the same subject (Flash was the poster):
I looked at a fleet of 7.3 PSD that we track monthly. The fleet has 81 units so there are hundreds, if not thousands of test results I am looking at. I am going to use the criteria of which has the lowest average iron in analysis. This is Delo 15w-40 against Rotella T 15w-40. By somewhere around 40% lower iron, the Rotella T wins. For whatever reason, the reports are not showing TBN on the Delo but the Rotella even after 10,000 miles is averagely showing a double digit TBN.
I wouldn't use 10W-40 regardless. You may want to follow your owner's manual if you're still under warranty.
That's actually a really good point guys. I originally thought you were asking about Delo vs. Rotella for a diesel. There's really no reason to use 15W-40 in a newer gasser.
because the 5.4 shears the 5w 20 oil and the valve train with the 5w20 becomes loud i only started using it because the engine does not shear the oil and my friend has been using it for 195,000 miles now he had the same problem and now there is no problem all of his oil tests came back bellow normal.
i have tried all i have used 5w20 5w30 10w30 and now the gas mileage in my expy has gone up just a little with 5w 20 in it i got 13.6 miles a gallon i am getting 14.7 and i got my oil results back today using the rotella there were no measurable amounts of bearings or aluminum iron was way below normal
because the 5.4 shears the 5w 20 oil and the valve train with the 5w20 becomes loud i only started using it because the engine does not shear the oil and my friend has been using it for 195,000 miles now he had the same problem and now there is no problem all of his oil tests came back bellow normal.
How do you know it’s shearing down the oil? All engines will run slightly louder with light oils in them.
I'd suspect a UOA would indicate shear by way of the vosciosity at 100 deg C. What was your viscosity? Do you KNOW it is shearing, or do you just suspect it to be?
All oils will shear some, including the Rotella. That's just what happens.
While it might not hurt anything, 15W-40 does seem a bit "thick" for an '03 5.4.
Rotella is a fine oil, but not exactly sure it is the best for your application. I really like the Chevron Supreme 10W-30 and would use it with confidence in your Expy.
yes the test results showed it sheared a lot i had the chevron in there last time but i might switch back to that or to rotella t 10w30 or royal purple
Well, if that's the case maybe I'd try something different too!
How many miles on the used oil?
What was the viscosity of the used oil at 100 deg C?
Thanks!
I'm confused....
Isn't a viscosity of 14 cst approx a 42 or 43 weight oil? And this UOA was on Rotella 15W-40, correct? Or was it the Chevron 10W-40?
Either way it appears both stayed solidly in-grade.
So how do you draw the conclusion the oil had suffered from high shear? Based just on that number (visciosity) it would seem the oil had performed just fine.
Thanks again.
edit to add: unless you understood the 14 to mean the used oil tested at 100 deg C was measured as a 14 WEIGHT oil. That is WAY different from 14 cst.
Could this explain the confusion?