Using Rotella T6 5w40 in Ranger

[GumbyJarvis]

only 700 miles in on this OCI and Im already prepping for the next.
Found Rotella T6 jugs on Craigslist, 2 for 25$, guys selling it because
"My Jetta died, to keep with GM, I will be using Dexos1 from now on"
Also has some filters but I am good without VW fiters..

Question, my truck specs 5w20, I have run 0w20, 5w20, 5w30, 10w30 grades before, no issues, ive run High Mileage oil in 10w30, no Issues, Synthetic, No Issues, Dino, again no issues.

Would a 5w40, synthetic HDEO blow up? lol.

 

[dave1251]

Would it blow your engine up? Hardly there are plenty of Ford Rangers out there using 15W40 in fleet use. You will take a slight hit on your MPG.

 

[simple_gifts]

If all you got is a hammer...

 

[CourierDriver]

Some friends of mine drove ford vans on the road doing expediting and changed to a 5w40 oil, gas mileage went to pot and Ford did not recommend using the 5w40 , but they were in new model v8.

Just to be sure I would call Ford. There were some cam failures on newer ford trucks and cars where guys went up in oil weights and caused engine head failure and cam shaft left town. I would check it out on a Ford truck forum IMHO, engine change outs these days are about 4000 bucks if your lucky.

 

[Rand]

use it with no issues. maybe lose a mpg if you do short tripping in the cold.

 

[CourierDriver]

From Bob is the oil guy, home pages, good data for all of us.

We left off discussing that a 0w30 grade oil is not thinner than a 10w30 oil. They both have the same thickness at operating temperature. The 0w30 simply does not get as thick on cooling as the 10w30. Both are still way to thick to lubricate an engine at startup.

I have heard several people say that Porsche specifically prohibits a 0W-XX engine oil, that it is too thin. Now here is the partial truth I spoke of earlier. We will discuss multi-grade oils. Earlier we said that a straight 30 grade oil has a thickness of 10 at the normal operating temperature of your engine. The multi-grade oils 0w30 and 10w30 also have a thickness of 10 at 212°F.

The difference is at 75°F, your startup temperature in the morning.

Oil Type Thickness at 75° F Thickness at 212° F
Straight 30 250 10
10W-30 100 10
0W-30 40 10
Straight 10 30 6
( Oil Type varying Thickness )

Now you can see that the difference between the desired thickness your engine requires ( = 10 ) is closest to the 0w30 oil at startup. It is still too thick for normal operation. But it does not have far to go before it warms up and thins to the correct viscosity. Remember that most engine wear occurs at startup when the oil is too thick to lubricate properly. It cannot flow and therefore cannot lubricate. Most of the thick oil at startup actually goes through the bypass valve back to the engine oil sump and not into your engine oil ways. This is especially true when you really step on that gas pedal. You really need more lubrication and you actually get less.

Note that a straight 10 grade oil is also too thick for your engine at startup. It has a thickness of 30. Yet at operating temperatures it is too thin having a thickness of 6. It needs to be around 10. The oil companies have added viscosity index improvers or VII to oils to solve this dilemma. They take a mineral based oil and add VI improvers so that it does not thin as much when it gets hotter. Now instead of only having a thickness of 6 when hot it has a thickness of 10, just as we need.

The penalty is the startup thickness also goes up to 100. This is better than being up at 250 as a straight 30 grade oil though. Oil with a startup thickness of 100 that becomes the appropriate thickness of 10 when fully warmed up is called a 10w30 grade motor oil. This is NOT as thick as a straight 30 grade oil at startup and it is NOT as thin as a straight 10 grade oil at full operating temperature.

The downside of a mineral based multi-grade oil is that this VII additive wears out over time and you end up with the original straight 10 grade oil. It will go back to being too thin when hot. It will have a thickness of 6 instead of 10. This may be why Porsche (according to some people) does not want a 0w30 but rather a 10w30. If the VII wears out the 0w30 will ultimately be thinner, a straight 0 grade oil. When the VII is used up in the 10w30 oil it too is thinner. It goes back to a straight 10 grade oil. They are both still too thick at startup, both of them. The straight 0 grade oil, a 5 grade oil and a 10 grade oil are all too thick at startup.

This is just theory however. With normal oil change intervals the VI improver will not wear out and so the problem does not really exist. In fact, oils do thin a little with use. This is partly from dilution with blow by gasoline and partly from VI improvers being used up. What is more interesting is that with further use motor oils actually thicken and this is much worse than the minimal thinning that may have occurred earlier.
Synthetic oils are a whole different story. There is no VI improver added so there is nothing to wear out. The actual oil molecules never wear out. You could almost use the same oil forever. The problem is that there are other additives and they do get used up. I suppose if there was a good way to keep oil clean you could just add a can of additives every 6 months and just change the filter, never changing the oil.



When the additives wear out in a synthetic oil it still has the same viscosity. It will not thin as a mineral oil. The fear that some say Porsche has that oils thin when the VII runs out is not applicable to these synthetic oils. These oils will always have the correct thickness when hot and will still be too thick at startup as with all oils of all types, regardless of the API / SAE viscosity rating.

Automotive engine manufacturers know these principals of motor oils. They know there is thinning or thickening that will occur. They take these things into account when they write that owners manual. Mineral oil change recommendations will generally include shorter time intervals than those of synthetic oils.

The reality is that motor oils do not need to be changed because they thin with use. It is the eventual thickening that limits the time you may keep oil in your engine. The limit is both time itself (with no motor use) and/or mileage use. The storage of motor oil in your garage, particularly mineral based oils, slowly ages the oil limiting its use later. Do not store huge volumes of oil in your garage that is exposed to extremes of temperature.




















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[Garak]

Originally Posted By: GumbyJarvis
Would a 5w40, synthetic HDEO blow up? lol.


While CourierDriver's point to check some Ford specific forums is a good idea, I wouldn't sweat it too much. It's not going to be optimal, but I doubt that in your climate that you'd have much to worry about.

 

[KevGuy]

That is the exact oil I use in my quad