Synthetic oil question
 

I own a 2011 F-350 king ranch that only has 14,700 miles on it mostly pulling my 42 ft 5th wheel. I have been using rotella T6 full synthetic oil in it since the first oil change. Does synthetic oil break down over time or can it be left in until it reaches it's mileage limit. I normally only put about 3-4 thousand miles on the truck each year. I have called several dealerships with this question and gotten a variety of answers.Any feedback would be greatly appreciated. Thanks

Much like gasoline, motor oil degrades because of the hydrocarbons in the product. Synthetic motor oil isn't actually 100% synthetic; it still has petroleum products in it, which means hydrocarbons.

I don't know to what extent it will degrade, or how long it'll take, but it will get "funky" after awhile.

Typically, it's a good idea to change the oil at the mileage limit, or at a six month interval, whichever comes first.

Hi Kingranch, welcome to FTE!

Your diesel supplement says the change interval can be up to 10,000 miles or 1 year. I would change it at least yearly.

A 6.7L can be $20k+ to replace an engine assembly, why skimp on $100 in oil once a year? Over the life of my truck I've spent maybe $2,500 on doing oil changes every 5k instead of the 7.5k per the book, and easily $20,000+ on fuel. Not that big a cost over 8 years.

Oil is basically the lifeblood of any engine. A DIY oil change is 60 - 80 bucks plus fuel filters for another 30 - 40 dollars, at a service facility, not too much more. I don't put too many miles on mine per year either, but think a spring and late fall/early winter change is well worth those few bucks. Rotella and several others meet the Ford spec and that's all you really need to really concern yourself over as far as oil breakdown. I use Motorcraft oil and filters in my truck and Rotella and Purolator filters in my diesel powered tractor and both do well. Of course, others will have varying opinions and what makes this sooooo much fun:D

Synthetic oil question
 

I would go with a yearly change even though you aren't putting very many miles on it. I also wouldn't use synthetic either, but that is just a personal preference. I have put over a million miles on diesels in the past 5 years using conventional Rotella T with no issues at all and it costs a lot less.

Thanks for the feedback guys, I believe I will go with yearly oil changes then, but still stick with synthetic.

Once a year is fine. Mileage is far more important than time.
Probably even more important though is the load on the engine. Obviously your 14 k miles is harder than someone not towing as often or as much. Should that mean an increase in changes? Up to u. I think you will be ok with yearly ...or start of winter/summer. If you wish to keep things optimum

dont do it i used syn oil and it blew my injectors oil seals in 2, 5, 6, 8, stay with convent oil

Oh please elaborate.

At NO time is conventional better than synthetic. Never.

Under super hot stress conditions like a race car engine..20w 50 does good protection with conventional.

That is the only example of a time when conventional is close to synthetic from a performance point of view.

Outside of that zero. In the cold? It's not even remotely close comparable.

Go synthetic and enjoy.

there are lots of times that conventional oil is a better choice. Synthetic oil ONLY refers to the base stock. Has nothing to do with the additive package. The correct conv oil with a good additive pack will preform better than a syn with the wrong or bad additive pack. keeping the additive pack fresh is important and a good reason to change oil, I am NOT anti syn. I use them in many applications, but each application is different. If the cost of the syn oil prevents you from changing the oil when it should be changed conv would be better. There are just as many high mile engines with conv oil than ones running syn. the choice is up to you. If you operate in extreme cold or heat syn might be a good choice

Bobv....
#1 I made no mention of price. If cost of concern in all reality I would have to ask how did you acquire an expensive piece of equipment that is not cheap to run in the first place....but yet one can't afford synthetic? Ok.

#2 I made no statement that conventional is garbage. But it is not on the same level as synthetic except in a few very rare cases.

#3 additive packs? All that? Wow. Not going to entertain that. We are talking about oil for the crankcase here not the next lunar missile off to mars.
The normal brands are up to snuff and if not go to the next one.
I would still like to hear where conventional is better than synthetic in the real world engines we run.
Price does not count here. Additives? Well I guess if you can find that rare synthetic example that does not meet requirements...I'm sure I can find a conventional brand likewise. So that is a wash. All things being equal, and price irrelevant since we are talking of performance there is no example of conventional oil better than synthetic. None. Btw, heat is the one area where certain conventional can come close to synthetic. 20w 50 is about it. That is the only time conventional is in the same ball park.

there are times and places for synthetic and conventional oil.
i would much prefer to have a fully synthetic oil in any HEUI engine, or really any equipment that needs to work hard, and keep working.
poorly running HEUI engines can smooth out, just from changing to synthetic oil.

on the other hand, for running around and getting groceries in your civic, conventional oil is all you need.

when it comes down to it, conventional oil is easier to break down, doesn't take heat as well, and also is not as good at dissipating heat either.


if you can afford synthetic, then get it. why not?

If you have ANY concerns, stay with the oil the manufacturer recommends and uses. I've used both and tend to stay with the usual Motorcraft diesel blend, but there for sure is no reason that a good synthetic oil wont work just as well. As far as that being the cause of wrecking injectors - nahhh. You had another pressure related problem that your mechanic cured.

Kingranch,

I have a 2006 KingRanch w/a 6.0 Diesel which sits a lot, takes mostly short trips except when pulling the 5'er & have spent a lot of time/money on this very question so maybe I can help here :-wink

It takes me about 16 Months to get 5,000 Miles on my Truck & I too use Rotella T6, now before everyone says u must follow a 9 year old book & change the Oil every 12 months, think about the advances in modern Oil.

I have been doing this for quite some time & sending an oil sample to BlackStone Labs after every oil change. They continue to tell me to run the oil longer (which I don't run longer than 5k) because the TBN reading stays strong @ 5.6-8.1 :-whud

The TBN only needs to be greater than 1 to protect your Engine adequately & if I can run nearly 1.5 years (5,000 miles) between changes & the Oil still has better protection properties than most Oil's right outta the jug, than Rotella T6 proves itself to me :-drink

:-arrgh:-arrgh WTF why is it NOT posting my whole Reply (twice now) :-arrgh:-arrgh:-arrg

Note: apparently FTE will NOT let u post using a "greater than" Symbol,
if u use one everything u wrote after that will NOT post :-roll

If I ask which is better, a Mach truck or a Honda Accord, you would probably answer depends on what you job they are going to do. Hauling 12 yards of dirt across town the Mack would be better, but loading up the family to go shopping, maybe not. This is what I am saying. You say syn are "BETTER". Better at what? I really comes down to the job you are asking it to do. In MENNY applications the additive pac is more important than the base stock, and there are some really good conv oil base stocks out there now. In MOST applications syn are a good choice.
In engine oil the reason to change the oil is more about the additive pac depletion and impurities then the condition of the base stock. Again, I know the advantages of GOOD syn oils, but saying it is always better is just a little TOO strong of a statement. It really comes down to the job you ask of it. Myself, and all the OEMs that DON'T require syn motor oil, say you still need to follow the manufacturers recommendations for oil change intervals. I do believe the GOOD conv oil, changed at the recommended intervals, will be better in the long run for the engine, then syn that are used in extended intervals. Do not ignore the additives, syn oil with no additives will kill an engine. They need to be there to counter the acids and the crap formed from the combustion process. There is nothing wrong with running a syn. If you want to run it that is fine, but thinking your engine is better protected MIGHT not be true.
Syn do have advantages, and they do have there place, the same is true for conventional oils.

Bitter recheck your TBN numbers!
some good reading
Do I Need a TBN?

i didn't say that synthetic oil is better. (even though it is)
conventional oil has poor oxidation stability at prolonged high temperatures.
also conventional oil has a harder time staying at its rated viscosity levels at higher temperatures.
your typical petroleum based conventional oil will decompose at high temperatures, and through many heat ups and cool downs. (short trips)
conventional oil can also give slow circulation during cold starts.
in some studies conventional oil have taken as long as 3 minutes to reach the rocker arms in a cold engine!
the heat issues is a big thing in our turbo charged trucks.
in any turbo charged vehicle actually.
conventional oil is a lot more likely to cook your bearings if not allowed to properly cool before the vehicle is turned off.

conventional oil and synthetic oil both come from the ground, but that's about the only thing they have in common.

sources: Pennzoil Lubrication and wear protection certification.

also, its many, not MENNY. :-X22

It's seeing the greater than sign as the opening to a code tag, just have to put a space behind it to use it as a character. Tags like < B> and < /B> are used for starting and ending bold text, replace b with i for italics, u for underline, s for strike though :-X22

< b> Hello < /b>
< i> Hello < /i>
< u> Hello < /u>
< s> <s> Hello </s> < /s>
(you can't see the tags without the space because FTE hides the codes and just shows the formatted text)

Great Resource: Motor Oil University

Motor Oil 101 - Bob is the Oil Guy - Bob is the Oil Guy

Post #10
"At NO time is conventional better than synthetic. Never."
that sounds like you are saying syn are better to me.
You arguments are all valid and thinks that should be considered. There are a LOT of diesel rigs running lots of miles running good conv oil. I can give lots of personal examples. I have also seen the mentality that sense I am running syn I don't have to change the oil. It really is a personal decision. For rig that sits a lot and only short drive the acids will build up fast. Reg oil, changed more often, will give better protection in the long term. Thinking that sense its syn I can let it stay is totally forgetting the reason the oil needs change.


BTW its coke, not cook

Take a look and post #10 again. That's not me lol.
And I don't agree with letting synthetic oil go longer in most cases. I also did not say that either.

Also again, coke is a soft drink. Cook is correct. :-X22

Synthetic oil question
 

Coke is correct ;)

I am sorry about that, using my cell phone and its hard to keep track.

I'm saying in the context that I'm using the word is correct.
I mean cook as in burn.

Just saying :-X04

Anything is possible when you don't know what you are talking about

That's cool. :-X22
Let's move on.

Yep, you already know everything. its a waste of time for the rest of us to post here.

There you go putting words in my mouth again.
I repeat let's move on and get this thread back on topic...

Ive always used Synthetic, in my class 8 tractor Freightliner with Detroit and my F450, 6.7 and my old F350 6.0L The 6.0 had just over 300,00miles when I traded it in, and still running strong on a local ranch, Two reasons Synthetic does not break down as fast, confirmed by oil samples, the other reason, ITS NOT FOSSIL OIL so I'm not paying "Big Oil" I give them enough with all the fuel I use. As previously stated, it kind of depends what your using your truck for, mine are over the road hot shots, and yes I pull heavy quite often, I know guys who use conventional oils, they claim a cost savings, but using a good oil sample I run mine longer therefore less oil changes, (less time in the shop for oil change) I could install a bypass oil system and run even longer, but sometimes I like to come home for a day off to get my oil changed. Run what your comfortable with..its your truck, your money. I guess you could strattle the fence and go semi synthetic like we put in the gassers.

Synthetic oil question
 

I use conventional in my Kenworth with a cat c15. The company I am leased on with buys their oil in bulk and I can get Mobil delvac for $8.95 per gallon. I get my filters at a 50% discount through them too, so both fuel filters, oil filter and 10 gallons of oil only costs me $112. Synthetic oil alone would cost twice that much.

I use synthetic in my super duty, but that is 7 quarts once a year instead of 10 gallons every other month.

Unless I am missing something here, my TBN # is good :confused:

This does scare me a little now though & maybe I should just change the damn OIL once a year even if I don't hit 5,000 miles just to be safe. I thought I was doing the right thing by having the oil tested & listening to them as far as extending the changes :-banghead

You guys really got me thinking now, good timing though as my next 1 year mark is in about 1 month :-wink

This is my basic philosophy on engine oil:
You'll never end up with regrets down the road that you over-changed your engine oil. Its not a marathon race.


I know the diesel service is more expensive and we all like to save what we can, but in my 6.2 gasser I run Penzoil Platinum and change it when the OCI reads around 40%. I don't bother with analysis because the testing costs half the price of my oil change.

Not to criticize anyone's opinion on time vs mileage, or synthetic vs conventional oil, but really anyone who considers these issues is ultimately taking good care of their vehicle.
With my 7qt gas truck I use full synthetic, changed once a year (about 10k miles).

I switched from conventional oil to Rotella T6 full synthetic. I couldn't believe the HUGE difference it made just with my cold starts every morning living here in the Northeast!

What weights are you using? The diesel supplement recommends certain weights for different temperatures.
Where I am, its not uncommon for the temp to go down to -15 to -20C for a month in the winter. In summer it can range from 10 to 30C
Looks like the 5w40 is a good choice for that temp range?

Would you still use 5w40 in summer hauling a 14k fifth wheel? or go lighter?

Welcome to the site! I'm using 5w40 all year long..

Only -20C? Southerner...